Halacha

הלכה א
כָּל הַשִּׁעוּרִים הָאֵלּוּ שְׁנָּתְנוּ חֲכָמִים לְדָבָר הָאָסוּר שֶׁנִּתְעָרֵב בְּמִינוֹ הַמֻּתָּר בְּשֶׁלֹּא הָיָה הַדָּבָר הָאָסוּר מְחַמֵּץ אוֹ מְתַבֵּל. אוֹ דָּבָר חָשׁוּב שֶׁהוּא עוֹמֵד כְּמוֹת שֶׁהוּא וְלֹא נִתְעָרֵב וְנִדְמָע בְּדָבָר הַמֻּתָּר. אֲבָל אִם הָיָה מְחַמֵּץ אוֹ מְתַבֵּל אוֹ דָּבָר חָשׁוּב אוֹסֵר בְּכָל שֶׁהוּא:
כסף משנה
1.
All the above measures given by our Sages with regard to a forbidden substance being mixed with a permitted substance of the same type apply when the forbidden substance is not a leavening agent, a spice, or an important entity that is discrete and is not mixed together with or blended with the permitted substance.1I.e., it does not become mixed with the forbidden substances into a single blend, nevertheless, it cannot be distinguished from the kosher substances. If, however, [the forbidden substance] is a leavening agent, a spice, or an important entity, even the slightest amount of it causes [the entire mixture] to be forbidden.2The presence of the forbidden substance is never nullified no matter how great the ratio between it and the permitted substances. Needless to say, this stringency was instituted by Rabbinic degree. As mentioned above, according to Scriptural Law, a simple majority is sufficient to nullify the presence of an entity.

הלכה ב
כֵּיצַד. שְׂאוֹר שֶׁל חִטִּין שֶׁל תְּרוּמָה שֶׁנָּפַל לְתוֹךְ עִסַּת חִטִּין שֶׁל חֻלִּין וְיֵשׁ בּוֹ כְּדֵי לְחַמֵּץ הֲרֵי הָעִסָּה כֻּלָּהּ מְדֻמָּע. וְכֵן תַּבְלִין שֶׁל תְּרוּמָה שֶׁנָּפְלוּ לִקְדֵרַת חֻלִּין וְיֵשׁ בָּהֶן כְּדֵי לְתַבֵּל וְהֵן מִמִּין הַחֻלִּין הַכּל מְדֻמָּע. וְאַף עַל פִּי שֶׁהַשְּׂאוֹר אוֹ הַתַּבְלִין אֶחָד מֵאֶלֶף. וְכֵן שְׂאוֹר שֶׁל כִּלְאֵי הַכֶּרֶם לְתוֹךְ הָעִסָּה אוֹ תַּבְלִין שֶׁל עָרְלָה לְתוֹךְ הַקְּדֵרָה הַכּל אָסוּר בַּהֲנָיָה:
כסף משנה
2.
What is implied? When yeast from wheat that is terumah falls into a dough of ordinary wheat [flour] and it is of sufficient quantity3If, however, there is not enough to cause the dough to leaven, it is not considered a leavening agent and its presence can be nullified [the Rambam's Commentary to the Mishnah (Orlah 2:6-7)]. to cause the dough to leaven, the entire dough is considered as having been mixed with terumah.4And must be sold to a priest at the price of terumah. Similarly, if spices that are terumah fall into a pot of ordinary food [containing] the same substance,5If, however, they do not contain the same substance, according to the Rambam (loc. cit.), we see if their flavor can be detected or not. If it cannot be detected, the mixture is permitted. when [the forbidden spices] are of sufficient quantity to season [the dish], the entire [dish] is considered as having been mixed with terumah. This applies even if the ration between the yeast and the spices [to the permitted substances] is 1:1000.
Similarly, if yeast from mixed species grown in a vineyard fall into a dough or spices of orlah fall into a pot, it is forbidden to benefit from the entire [mixture].

הלכה ג
דָּבָר חָשׁוּב שֶׁהוּא אוֹסֵר בְּמִינוֹ בְּכָל שֶׁהוּא שִׁבְעָה דְּבָרִים וְאֵלּוּ הֵן. אֱגוֹזֵי פֶּרֶךְ. וְרִמּוֹנֵי בְּדַן. וְחָבִיּוֹת סְתוּמוֹת. וַחֲלַפוֹת תְּרָדִין. וְקִלְחֵי כְּרוּב. וּדְלַעַת יְוָנִית. וְכִכָּרוֹת שֶׁל בַּעַל הַבַּיִת:
כסף משנה
3.
Even the smallest amount of an important entity [that is forbidden] can cause a mixture of its own type to become forbidden. The seven entities that follow are considered as important: nuts from Perach,6Perach and Baden are names of places. These and the following terms are defined in the Rambam's Commentary to the Mishnah (Orlah 3:8). pomegranates from Baden, sealed barrels,7The Rama (Yoreh De'ah 134:2) states that this applies only when the barrels are large and therefore important. A small barrel is not important and its presence can be nullified by a simple majority. beet shoots, cabbage heads, Greek squash, and loaves baked by a private person.8In contrast to those baked by a baker.

הלכה ד
כֵּיצַד. רִמּוֹן אֶחָד מֵרִמּוֹנֵי בְּדַן שֶׁהָיָה עָרְלָה וְנִתְעָרֵב בְּכַמָּה אֲלָפִים רִמּוֹנִים הַכּל אָסוּר בַּהֲנָיָה. וְכֵן חָבִית סְתוּמָה שֶׁל יֵין עָרְלָה אוֹ שֶׁל כִּלְאֵי הַכֶּרֶם שֶׁנִּתְעָרְבָה בְּכַמָּה אֲלָפִים חָבִיּוֹת סְתוּמוֹת הַכּל אֲסוּרִים בַּהֲנָיָה. וְכֵן שְׁאָר הַשִּׁבְעָה דְּבָרִים:
כסף משנה
4.
What is implied? If one pomegranate from Baden that was orlah became mixed with several thousand other pomegranates, it is forbidden to benefit from the entire mixture.9I.e., all the pomegranates are considered as if they are the pomegranate that is orlah.
The Radbaz mentions opinions that state that one may throw away the value of the forbidden pomegranate, but then benefit from the entire mixture. He, however, brings support for the Rambam's position.
The Shulchan Aruch (Yoreh De'ah 101:1) appears to support the Rambam's ruling. Note, however, the comments of the Siftei Cohen 110:2 who writes that even though a Jew may not benefit from any one of the forbidden pomegranates himself, he may sell the entire mixture to a gentile, minus the price of the forbidden pomegranate. See also the notes to Halachah 7.
Similarly, if a sealed barrel of wine that is orlah or that is a product of mixed species from a vineyard that became mixed with several thousand sealed barrels, it is forbidden to benefit from the entire quantity.

הלכה ה
וְכֵן חֲתִיכָה שֶׁל נְבֵלָה אוֹ שֶׁל בְּשַׂר בְּהֵמָה אוֹ חַיָּה אוֹ עוֹף אוֹ דָּג הַטְּמֵאִין שֶׁנִּתְעָרְבָה בְּכַמָּה אֲלָפִים חֲתִיכוֹת הַכּל אָסוּר עַד שֶׁיַּגְבִּיהַּ אוֹתָהּ חֲתִיכָה. וְאַחַר כָּךְ יְשַׁעֵר הַשְּׁאָר בְּשִׁשִּׁים. שֶׁאִם לֹא הִגְבִּיהָהּ הֲרֵי הַדָּבָר הָאָסוּר עוֹמֵד וְלֹא נִשְׁתַּנָּה וְהַחֲתִיכָה חֲשׁוּבָה אֶצְלוֹ שֶׁהֲרֵי מִתְכַּבֵּד בָּהּ לִפְנֵי הָאוֹרְחִין:
כסף משנה
5.
Similarly, when a piece of meat from a nevelah or from a non-kosher species of animal, beast, fowl, or fish become mixed with several thousand other pieces of meat, the entire mixture is forbidden until one separates that piece of meat and makes certain that there is sixty times its measure.10This refers to an instance when the forbidden piece of meat was cooked with the other pieces. For if one does not separate [the forbidden piece of meat], it will continue to be present and it will not have changed.11If its form changes, different rules apply, as apparent from Halachah 11. And this piece of meat is important to him, for he receives honor [by serving it] to guests.12The Tur and the Shulchan Aruch (Yoreh De'ah 109:1) state that if a piece of meat is not of the type that will bring a person respect by serving it to guests, the stringency mentioned in this halachah does not apply.
Tosafot (Chulin 100a) explains that even though in practice, the piece of meat will not bring honor to the person - because since it is forbidden, he cannot serve it - it is placed in this category, for were it not to be forbidden, it would bring him honor.

הלכה ו
וְהוּא הַדִּין בַּחֲתִיכָה שֶׁל בָּשָׂר בְּחָלָב אוֹ שֶׁל חֻלִּין שֶׁנִּשְׁחֲטוּ בָּעֲזָרָה שֶׁהֲרֵי הֵן אֲסוּרִים מִדִּבְרֵיהֶן בַּהֲנָיָה כְּמוֹ שֶׁיִּתְבָּאֵר בְּהִלְכוֹת שְׁחִיטָה אוֹסְרִין בְּכָל שֶׁהֵן עַד שֶׁיַּגְבִּיהַּ אוֹתָן. וְכֵן גִּיד הַנָּשֶׁה שֶׁנִּתְבַּשֵּׁל עִם הַגִּידִין אוֹ עִם הַבָּשָׂר בִּזְמַן שֶׁמַּכִּירוֹ מַגְבִּיהוֹ וְהַשְּׁאָר מֻתָּר שֶׁאֵין בַּגִּידִים בְּנוֹתֵן טַעַם. וְאִם אֵינוֹ מַכִּירוֹ הַכּל אָסוּר מִפְּנֵי שֶׁהוּא בְּרִיָּה בִּפְנֵי עַצְמוֹ הֲרֵי הוּא חָשׁוּב וְאוֹסֵר בְּכָל שֶׁהוּא:
כסף משנה
6.
The same laws apply with regard to a piece of meat [cooked] with milk13There is an important insight associated with this ruling. The stringency relating to a piece of meat from which one receives honor applies only when the meat is inherently forbidden. When, however, a piece of kosher meat falls into a stew of non-kosher meat, it is not considered a piece of meat from which one receives honor, for it is not inherently forbidden. What is forbidden is the flavor of the non-kosher meat and that flavor is not a substance from which one receives honor.
This does not apply with regard to milk and meat. Although it is absorbing the milk that causes the meat to be considered forbidden, once it absorbs that milk, it becomes inherently forbidden. For both of the substances are themselves permitted, it is their mixture that is forbidden by the Torah (Radbaz).
or an ordinary animal that was slaughtered in the Temple courtyard, for it is forbidden to benefit from [the latter] according to Rabbinic decree,14I.e., this stringency is applied even though we are speaking only about a Rabbinic prohibition (Kessef Mishneh). as will be explained in Hilchot Shechitah.15Chapter 2, Halachah 3. Even the slightest amount of them causes [a mixture] to become forbidden until they are removed.
Similarly, when a gid hanesheh was cooked with other similar tissue or with meat, when it can be recognized, it should be removed and the remainder is permitted. For giddim do not impart flavor.16The Lechem Mishneh states that this is speaking about a situation when the gid hanesheh was cooked without its fat. Otherwise, 60 times its volume is required, for the fat does impart flavor. If one cannot recognize it, the entire mixture is forbidden. For [the gid hanesheh is considered as a created being in its own right.17The Shulchan Aruch (Yoreh De'ah 100:1) gives the following criteria for a creation in its own right: It must be alive, in contrast to a kernel of wheat. It must be inherently forbidden, in contrast to a kosher fowl that was slaughtered improperly. It must be a complete entity to the extent that were it to be divided it would no longer be referred to with that name in contrast to non-kosher fat. And it must actually be whole, in contrast to a gid hanesheh that was cut in half. Hence, it is significant; no matter how small it is, it causes [a mixture] to become forbidden.18This principle applies with regard to all entities that are creations in their own right. Until they are removed, the mixture is forbidden regardless of the ratio of kosher to nonkosher substances. Once they are removed, the ratio must be 60:1 (ibid.:2).

הלכה ז
וְכֵן כָּל בַּעֲלֵי חַיִּים חֲשׁוּבִין הֵן וְאֵינָם בְּטֵלִין. לְפִיכָךְ שׁוֹר הַנִּסְקָל שֶׁנִּתְעָרֵב בְּאֶלֶף שְׁוָרִים וְעֶגְלָה עֲרוּפָה בְּאֶלֶף עֶגְלוֹת. אוֹ צִפּוֹר מְצֹרָע הַשְּׁחוּטָה בְּאֶלֶף צִפֳּרִים אוֹ פֶּטֶר חֲמוֹר בְּאֶלֶף חֲמוֹרִים כֻּלָּן אֲסוּרִין בַּהֲנָיָה. אֲבָל שְׁאָר הַדְּבָרִים אַף עַל פִּי שֶׁדַּרְכָּן לִמָּנוֹת הֲרֵי אֵלּוּ עוֹלִין בְּשִׁעוּרָן:
כסף משנה
7.
Similarly, all living animals are significant and they never become nullified. Therefore, if an ox sentenced to be stoned to death19An ox sentenced to execution for goring a human being. See Chapter 4, Halachah 22. becomes intermingled with 1000 oxen, a calf whose neck is to be broken20This calf is an atonement offering brought by the elders of a city when there is an unresolved murder. See Hilchot Rotzeach , ch. 9. becomes intermingled with 1000 calves, a dove selected for a metzora21Tzara'at refers to a unique affliction of the skin resembling leprosy that afflicted a person because of he spoke lashon hora, unfavorable gossip. When the physical signs of his affliction have disappeared, the person must bring two doves as sacrifices. One is slaughtered and one is sent away, as stated in Hilchot Tumat Tzara'at 11:1. It is forbidden to benefit from the one that is slaughtered. becomes intermingled with 1000 doves, or a firstborn donkey22A firstborn donkey must either be either exchanged for a lamb and the lamb given to a priest or the donkey's neck must be broken (Exodus 13:13; Hilchot Bikkurim, ch. 12). becomes intermingled with 1000 donkeys, it is forbidden to benefit from any of them.23The Ra'avad differs with the Rambam's ruling, stating that all that is necessary is to destroy the benefit one would receive from one of the forbidden entities. The benefit from the remainder is permitted. The Kessef Mishneh points to Halachah 29 as indication that the Rambam would also accept the ruling stated by the Ra'avad. The Migdal Oz differs and maintains that the Rambam would not accept that ruling. As mentioned above, the Siftei Cohen 101:2 defends the position of the Kessef Mishneh, stating that the Rambam would allow one to sell the entire mixture to a gentile, minus the price of the forbidden article. With regard to other entities, even though it is customary to [sell] them by number,24The Tur and the Rama (Yoreh De'ah 110:1) cite the view of other Rishonim who state that whenever an article is always sold by number, not by a package, its presence is never nullified. they can be nullified according to the ordinary measures.

הלכה ח
כֵּיצַד. אֲגֻדָּה שֶׁל יָרָק מִכִּלְאֵי הַכֶּרֶם שֶׁנִּתְעָרְבָה בְּמָאתַיִם אֲגֻדּוֹת. אוֹ אֶתְרוֹג שֶׁל עָרְלָה שֶׁנִּתְעָרֵב בְּמָאתַיִם אֶתְרוֹגִים. הַכּל מֻתָּר. וְכֵן כָּל כַּיּוֹצֵא בָּזֶה:
כסף משנה
8.
What is implied?25I.e., what is an example of an article that is sold by number being nullified. When a bundle of vegetables that come from mixed species grown in a vineyard are mixed with 200 bundles or an esrog which is orlah is mixed with 200 esrogim, the entire quantity is permitted. Similar laws apply in all analogous situations.

הלכה ט
יֵרָאֶה לִי שֶׁכָּל דָּבָר שֶׁהוּא חָשׁוּב אֵצֶל בְּנֵי מָקוֹם מִן הַמְּקוֹמוֹת. כְּגוֹן אֱגוֹזֵי פֶּרֶךְ וְרִמּוֹנֵי בְּדַן בְּאֶרֶץ יִשְׂרָאֵל בְּאוֹתָן הַזְּמַנִּים. שֶׁהוּא אוֹסֵר בְּכָל שֶׁהוּא לְפִי חֲשִׁיבוּתוֹ בְּאוֹתוֹ מָקוֹם וּבְאוֹתוֹ זְמַן. וְלֹא הֻזְכְּרוּ אֵלּוּ אֶלָּא לְפִי שֶׁהֵן אוֹסְרִין כָּל שֶׁהֵן בְּכָל מָקוֹם. וְהוּא הַדִּין לְכָל כַּיּוֹצֵא בָּהֶן בִּשְׁאָר מְקוֹמוֹת. וְדָבָר בָּרוּר הוּא שֶׁכָּל אִסּוּרִין הָאֵלּוּ מִדִּבְרֵיהֶם:
כסף משנה
9.
It appears to me that every article that is significant to the inhabitants of a given place as nuts from Perach and pomegranates from Baden were significant in Eretz Yisrael in [the Talmudic] era causes a mixture to be forbidden if even the slightest amount becomes mixed in because of its importance in that time and in that era. The particular entities [referred to above] were mentioned because the slightest amount of them causes a mixture to be forbidden in every place. The same laws apply to articles similar to them in other places. It is clear that all of these prohibitions stem from Rabbinic decree.26For according to Scriptural Law, a substance mixed with substances of the same type are forbidden when there is a majority of the permitted substance. When mixed with substances of a different type, they are nullified when the taste can no longer be detected.

הלכה י
נָפַל רִמּוֹן אֶחָד מִן הַתַּעֲרֹבֶת הַזֹּאת לִשְׁנֵי רִמּוֹנִים אֲחֵרִים מֵרִמּוֹנֵי בְּדַן. וְנָפַל מִן הַשְּׁלֹשָׁה רִמּוֹן אֶחָד לְרִמּוֹנִים אֲחֵרִים. הֲרֵי אֵלּוּ הָאֲחֵרִים מֻתָּרִין שֶׁהֲרֵי הָרִמּוֹן שֶׁל תַּעֲרֹבֶת הָרִאשׁוֹנָה בָּטֵל בְּרֹב. וְאִם נָפַל מִן הַתַּעֲרֹבֶת הָרִאשׁוֹנָה רִמּוֹן לְאֶלֶף כֻּלָּן אֲסוּרִין. לֹא נֶאֱמַר בָּטֵל בְּרֹב אֶלָּא לְהַתִּיר סְפֵק סְפֵקָן שֶׁאִם יִפּל מִן הַתַּעֲרֹבֶת הַשְּׁנִיָּה לְמָקוֹם אַחֵר אֵינוֹ אוֹסֵר. וְכֵן כָּל כַּיּוֹצֵא בָּזֶה:
כסף משנה
10.
If one pomegranate from a mixture [of pomegranates including a forbidden pomegranate from Baden] falls into two other [permitted] pomegranates from Baden and then one of these three pomegranates fell into other pomegranates, the latter mixture is permitted. [The rationale is that the presence of] the pomegranate from the first mixture [which fell into the second mixture] is nullified because of the majority of permitted substances.27I.e., according to Scriptural Law; according to Rabbinic Law, both the first and the second mixtures are forbidden. If, however, [a pomegranate] from the first mixture falls into 1000 pomegranates, they are all forbidden.28For with regard to each of the pomegranates in the second mixture, there is a question if it is forbidden by Scriptural Law or not (Radbaz).
The Radbaz notes that the Rambam's ruling here appears to contradict his ruling in Hilchot Avodat Kochavim 7:10 where the Rambam rules that if a goblet used for idol worship becomes mixed with other goblets and then one from the first mixture falls into a second mixture, one may use the goblets of the second mixture. The Radbaz maintains that with this ruling, the Rambam changed his mind and adopted a more stringent position.
The Kessef Mishneh explains that the Rambam rules more stringently in this instance than with regard to idol worship because the prohibition against idol worship is universally known. The prohibition against benefiting from a significant entity, by contrast, is less recognized. Therefore there is need for greater stringency. Alternatively, here the Rambam is speaking about partaking of the forbidden mixture, while in Hilchot Avodat Kochavim, he is speaking about benefiting from the mixture. Obviously, there is greater reason to prohibited a substance from which one partakes.
The position followed by the Rambam in Hilchot Avodat Kochavim is followed by other Rishonim even with regard to a significant entity. The Shulchan Aruch (Yoreh De'ah 110:8) quotes the Rambam's view and the Rama adds further stringencies. The Turei Zahav 110:10 and the Siftei Cohen 110:3 mention the more lenient views.
[The concept that the presence of the forbidden pomegranate] was nullified because of the majority of permitted substances only when there is a multiple doubt involved:29Perhaps the pomegranate that fell from the first mixture into the second mixture was not forbidden by Scriptural Law. Even if it was forbidden, perhaps the pomegranate that fell from the second mixture was not forbidden by Scriptural Law. Thus there is a multiple doubt if an entity forbidden by Scriptural Law is present. i.e., that if one of the second mixture will fall into another place, it does not cause [that third mixture] to become forbidden. Similar laws apply in all analogous situations.

הלכה יא
נִתְפַּצְּעוּ אֱגוֹזִים אֵלּוּ שֶׁנֶּאֶסְרוּ כֻּלָּן מִפְּנֵי אֱגוֹז עָרְלָה שֶׁבֵּינֵיהֶן אוֹ נִתְפָּרְרוּ הָרִמּוֹנִים וְנִתְפַּתְּחוּ הֶחָבִיּוֹת וְנִתְחַתְּכוּ הַדְּלוּעִין וְנִתְפָּרְסוּ הַכִּכָּרוֹת אַחַר שֶׁנֶּאֶסְרוּ הֲרֵי אֵלּוּ יַעֲלוּ בְּאֶחָד וּמָאתַיִם. וְהוּא הַדִּין לַחֲתִיכַת נְבֵלָה שֶׁנִּדּוֹכָה בְּכָל הַחֲתִיכוֹת וְנַעֲשָׂה הַכּל כְּמוֹת שֶׁהִיא עוֹלֶה בְּשִׁשִּׁים:
כסף משנה
11.
If the nuts that were forbidden because of the nut that was orlah intermingled with them were cracked open, the pomegranates were taken apart, the barrels were opened, the squash was cut, or the bread was sliced after they became forbidden, [the presence of the forbidden entity] can be nullified if there is 201 times its volume.30As required with regard to the prohibitions of orlah and mixed species in a vineyard. I.e., the stringency of a significant article no longer applies, because the entities are no longer whole and in their present form, they are not significant. This law also applies with regard to a piece of forbidden meat31Which would be forbidden because one derives honor from serving it as stated in Halachah 5. Once it has been minced, the meat is no longer a piece from which one would derive honor [Shulchan Aruch (Yoreh De'ah101:6)]. that is minced together with other pieces and they are all [minced] in the same way, [the presence of the forbidden entity] can be nullified if there is 60 times its volume.

הלכה יב
וְאָסוּר לִפְצֹעַ הָאֱגוֹזִים וּלְפָרֵר הָרִמּוֹנִים וְלִפְתֹּחַ הֶחָבִיּוֹת אַחַר שֶׁנֶּאֶסְרוּ כְּדֵי שֶׁיַּעֲלוּ בְּאֶחָד וּמָאתַיִם שֶׁאֵין מְבַטְּלִין אִסּוּר לְכַתְּחִלָּה. וְאִם עָשָׂה כֵּן קוֹנְסִין אוֹתוֹ וְאוֹסְרִין עָלָיו כְּמוֹ שֶׁבֵּאַרְנוּ:
כסף משנה
12.
It is, however, forbidden to crack the nuts, take apart the pomegranates, open the barrels after they have become forbidden so that [the presence of the forbidden entity] can be nullified if there is 201 times its volume. For, as an initial and preferred measure, we do not nullify the presence of an entity.32The commentaries question the Rambam's statement, noting that in Chapter 15, Halachah 26, the Rambam states that we may nullify the presence of a substance forbidden by Rabbinic Law. Since the prohibition against these mixtures is Rabbinic in origin, seemingly, it would be possible to nullify their presence. If one does so, we penalize him and forbid [the entity] to him, as explained.33See Chapter 15, Halachah 25.

הלכה יג
שְׂאוֹר שֶׁל כִּלְאֵי הַכֶּרֶם וְשֶׁל תְּרוּמָה שֶׁנָּפְלוּ לְתוֹךְ הָעִסָּה לֹא בָּזֶה כְּדֵי לְחַמֵּץ וְלֹא בָּזֶה כְּדֵי לְחַמֵּץ וּבִשְׁנֵיהֶם כְּשֶׁיִּצְטָרְפוּ יֵשׁ בָּהֶם כְּדֵי לְחַמֵּץ. אוֹתָהּ עִסָּה אֲסוּרָה לְיִשְׂרָאֵל וּמֻתֶּרֶת לַכֹּהֲנִים. וְכֵן תַּבְלִין שֶׁל תְּרוּמָה וְשֶׁל כִּלְאֵי הַכֶּרֶם שֶׁנָּפְלוּ לְתוֹךְ הַקְּדֵרָה. וְלֹא בְּאֶחָד מֵהֶן כְּדֵי לְתַבֵּל וּבִשְׁנֵיהֶם כְּדֵי לְתַבֵּל. אוֹתָהּ קְדֵרָה אֲסוּרָה לְיִשְׂרָאֵל שֶׁהֲרֵי דָּבָר הָאָסוּר לָהֶם תִּבְּלָה. וּמֻתֶּרֶת לַכֹּהֲנִים:
כסף משנה
13.
[The following rule applies when] yeast that comes from mixed species in a vineyard and from terumah falls into dough and there is not enough of either of [the forbidden substances] alone to cause the dough to rise, but when the two are combined, there is enough to cause the dough to rise. This dough is forbidden to an Israelite, but permitted to the priests.34As mentioned in Halachah 1, if an entity is sufficient to cause a dough to leaven or to spice a pot, its presence can never be nullified. Although neither forbidden entity on its own is large enough to bring about this change, when the two are combined, this result is achieved. Therefore an Israelite is forbidden to partake of the dough or the pot. With regard to a priest, by contrast, since terumah is not forbidden to him, we do not say that an article forbidden to him brought about this change. For the mixed species alone is not of sufficient size. Hence, he is permitted to partake of the bread or the cooked food.
Similarly, when spices that come from terumah and from mixed species in a vineyard fall into a pot and there is not enough of either of [the forbidden substances] to spice the pot, but together there is enough of both of them to spice the pot, that pot is forbidden to an Israelite - for an entity forbidden to him spice it - and permitted to the priests.

הלכה יד
תַּבְלִין שֶׁהֵם שְׁנַיִם אוֹ שְׁלֹשָׁה שֵׁמוֹת מִמִּין אֶחָד אוֹ שְׁלֹשָׁה מִינִין מִשֵּׁם אֶחָד מִצְטָרְפִין לְתַבֵּל וְלֶאֱסֹר וְכֵן לְחַמֵּץ. כֵּיצַד. שְׂאוֹר שֶׁל חִטִּין וּשְׂאוֹר שֶׁל שְׂעוֹרִים הוֹאִיל וְשֵׁם שְׂאוֹר אֶחָד הוּא אֵינָן כְּמִין וְשֶׁאֵינוֹ מִינוֹ. אֶלָּא הֲרֵי הֵן כְּמִין אֶחָד וּמִצְטָרֵף לְשַׁעֵר בָּהֶן כְּדֵי לְחַמֵּץ בְּעִסָּה שֶׁל חִטִּין אִם הָיָה טַעַם שְׁנֵיהֶם טַעַם חִטִּין. אוֹ כְּדֵי לְחַמֵּץ בְּעִסָּה שֶׁל שְׂעוֹרִין אִם הָיָה טַעַם שְׁנֵיהֶם טַעַם שְׂעוֹרִים:
כסף משנה
14.
When there are two or three types of the same species of spice or three species of the same type, they can be combined to cause a pot to be forbidden when they spice it or when [a similar type mixture] causes dough to leaven.
What is implied? Yeast from wheat and yeast from barley are not considered as being two separate substances. Instead, since the category yeast is the same, they are considered as one substance and they can be combined to measure to see if they are sufficient to cause a dough of wheat to leaven if their combined flavor is that of wheat35If the combined flavor is not that of wheat, the dough does not become forbidden, because the yeast is considered as giving a different flavor to the dough. Hence the dough is forbidden only of that flavor is detectable.
The Ra'avad differs with the Rambam's ruling, offering a different interpretation of Avodah Zarah 65a, the Rambam's source. Significantly, their disagreement is mirrored by similar difference in interpretation by Rashi and Tosafot. Rashi and the Rambam follow one approach and Tosafot and the Ra'avad, the other.
or to cause a dough of barley to leaven if their combined flavor is that of barley.

הלכה טו
שְׁלֹשָׁה שֵׁמוֹת מִמִּין אֶחָד כֵּיצַד. כְּגוֹן כַּרְפַּס שֶׁל נְהָרוֹת וְכַרְפַּס שֶׁל אֲפָר וְכַרְפַּס שֶׁל גִּנָּה אַף עַל פִּי שֶׁכָּל אֶחָד מֵהֶן שֵׁם בִּפְנֵי עַצְמוֹ הוֹאִיל וְהֵם מִין אֶחָד מִצְטָרְפִין לְתַבֵּל:
כסף משנה
15.
What is meant by three species of the same type? For example, river parsley, parsley that grows in meadows, and parsley that grows in gardens. Although each of them has a distinct name, since they are of one type, they can be combined to [cause a dish to be forbidden if they] spice [it].

הלכה טז
עִסָּה מְחֻמֶּצֶת שֶׁנָּפַל לְתוֹכָהּ שְׂאוֹר שֶׁל תְּרוּמָה אוֹ שְׂאוֹר שֶׁל כִּלְאֵי הַכֶּרֶם. וְכֵן קְדֵרָה מְתֻבֶּלֶת שֶׁנָּפְלוּ לְתוֹכָהּ תַּבְלִין שֶׁל תְּרוּמָה אוֹ שֶׁל עָרְלָה וְשֶׁל כִּלְאֵי הַכֶּרֶם. אִם יֵשׁ בַּשְּׂאוֹר כְּדֵי לְחַמֵּץ אִלּוּ הָיְתָה הָעִסָּה מַצָּה. וּבַתַּבְלִין כְּדֵי לְתַבֵּל הַקְּדֵרָה אִלּוּ הָיְתָה תְּפֵלָה הֲרֵי הַכּל אָסוּר. וְאִם אֵין בָּהֶם כְּדֵי לְתַבֵּל וּלְחַמֵּץ יַעֲלוּ בְּשִׁעוּרָן. תְּרוּמָה בְּאֶחָד וּמֵאָה וְעָרְלָה וְכִלְאֵי הַכֶּרֶם בְּאֶחָד וּמָאתַיִם:
כסף משנה
16.
[The following rules apply when] yeast that is terumah or from mixed species from a vineyard falls into dough that is already leavened or spices that are terumah or from mixed species from a vineyard fall into a pot that has already been spiced. If there is enough [of the forbidden] yeast to cause the dough to leaven if it had been unleavened or there is enough of the spices to spice the pot had it been unspiced, the entire mixture is forbidden.36Although in actual fact the forbidden yeast or spices did not have an effect, because the dough leavened and the pot was spiced without them. Nevertheless, since they could have had an effect, they cause the dish to become forbidden.
Avodah Zarah 68a notes that when a dough is already leavened, adding yeast will spoil its flavor. Hence, seemingly, it should not be forbidden. Nevertheless, an exception is made with regard to dough, for when extra yeast is added to dough, that dough is then used to cause other doughs to leaven. Hence, it is not considered to be spoiled.
The Ra'avad understands the emphasis of the passage from Avodah Zarah differently and objects to the Rambam's ruling. He note that Avodah Zarah does not mention spices; the Rambam added those on the basis of his logic. And the Ra'avad, argues, that logic can be disputed. For the addition of yeast to the dough has an effect as explained. The addition of the spices, by contrast, have no effect - for the pot was already spiced. Why then do they cause the pot to be forbidden?
The Lechem Mishneh answers, that even according to the Ra'avad's understanding, the Rambam's logic can be defended, for the food from the heavily spiced pot could be used to spice other pots.
If they are of sufficient size to spice [the pot] or cause [the dough] to leaven, their presence can be nullified according to the required measure: terumah when [the mixture] is 101 times [the size of the forbidden substance] and mixed species in a vineyard when [the mixture] is 201 times [the size of the forbidden substance].

הלכה יז
הַתְּרוּמָה מַעְלָה אֶת הָעָרְלָה וְאֶת כִּלְאֵי הַכֶּרֶם. כֵּיצַד. סְאָה תְּרוּמָה שֶׁנָּפְלָה לְתִשְׁעָה וְתִשְׁעִים חֻלִּין וְאַחַר כָּךְ נָפַל לְכָל חֲצִי סְאָה שֶׁל עָרְלָה אוֹ שֶׁל כִּלְאֵי הַכֶּרֶם אֵין כָּאן אִסּוּר עָרְלָה וְלֹא אִסּוּר כִּלְאֵי הַכֶּרֶם. שֶׁהֲרֵי עָלָה בְּאֶחָד וּמָאתַיִם. וְאַף עַל פִּי שֶׁמִּקְצָת הַמָּאתַיִם תְּרוּמָה:
כסף משנה
17.
Terumah can [help] cause orlah and mixed species from a vineyard to be nullified.
What is implied? When a se'ah of terumah falls into 99 [se'ah of] ordinary produce and afterwards, a half se'ah of orlah or mixed species from a vineyard falls into the entire mixture, the prohibition against orlah or mixed species in a vineyard does not apply.37The mixture is, however, forbidden to Israelites and permitted only to priests, for the presence of the terumah is not nullified. For it is nullified because of the presence of 201 times [the size of the forbidden substance] even though a portion of the 201 is terumah.38This and the following halachah represent the Rambam's interpretation of Orlah 2:2 which is based on the Jerusalem Talmud.

הלכה יח
וְכֵן הָעָרְלָה וְכִלְאֵי הַכֶּרֶם מַעֲלִין אֶת הַתְּרוּמָה. כֵּיצַד. מֵאָה סְאָה שֶׁל עָרְלָה אוֹ שֶׁל כִּלְאֵי הַכֶּרֶם שֶׁנָּפְלוּ לְתוֹךְ עֶשְׂרִים אֶלֶף שֶׁל חֻלִּין נַעֲשֵׂית כָּל הַתַּעֲרֹבֶת עֶשְׂרִים אֶלֶף וּמֵאָה. וְאַחַר כָּךְ נָפַל לְכָל מֵאָה סְאָה סְאָה שֶׁל תְּרוּמָה הֲרֵי הַכּל מֻתָּר וְתַעֲלֶה הַתְּרוּמָה בְּאֶחָד וּמֵאָה. וְאַף עַל פִּי שֶׁמִּקְצָת הַמֵּאָה הַמַּעֲלִין אוֹתָהּ עָרְלָה אוֹ כִּלְאֵי הַכֶּרֶם:
כסף משנה
18.
Similarly, orlah and mixed species from a vineyard can [help] cause terumah to be nullified.
What is implied? When 100 se'ah of orlah or mixed species from a vineyard fall into 20,000 se'ah of ordinary produce, the entire mixture is thus 20,100 se'ah.39I.e., the presence of the orlah or the mixed species from the vineyard are nullified. Afterwards, a se'ah of terumah fell into every 100 se'ah, the entire [mixture] is permitted and the presence of the terumah is nullified because of the presence of 101 times [the original amount of terumah].40This example is the product of the Rambam's own deduction. Although the simple interpretation of Orlah, loc. cit., would imply that the concept stated in this halachah could also be derived from the situation described in the previous halachah, it does not work out mathematically. Hence, the Rambam had to find a new example. [This applies] even though part of the 100 that nullify its presence are orlah or mixed species from a vineyard.

הלכה יט
וְכֵן הָעָרְלָה מַעֲלָה אֶת כִּלְאֵי הַכֶּרֶם. וְכִלְאֵי הַכֶּרֶם אֶת הָעָרְלָה. וְכִלְאֵי הַכֶּרֶם אֶת כִּלְאֵי הַכֶּרֶם. וְהָעָרְלָה אֶת הָעָרְלָה. כֵּיצַד. מָאתַיִם סְאָה שֶׁל עָרְלָה אוֹ שֶׁל כִּלְאֵי הַכֶּרֶם שֶׁנָּפְלוּ לְאַרְבָּעִים אֶלֶף חֻלִּין. וְאַחַר כָּךְ נָפַל לְכָל מָאתַיִם סְאָה וּסְאָה שֶׁל עָרְלָה אוֹ שֶׁל כִּלְאֵי הַכֶּרֶם הַכּל מֻתָּר. שֶׁכֵּיוָן שֶׁבָּטֵל הָאִסּוּר שֶׁנָּפַל תְּחִלָּה נַעֲשָׂה הַכּל כְּחֻלִּין הַמֻּתָּרִין:
כסף משנה
19.
Similarly, orlah may [help] nullify mixed species from a vineyard and mixed species from a vineyard may [help] nullify orlah. Mixed species from a vineyard may [help] nullify [the presence of other] mixed species from a vineyard and orlah may [help] nullify [the presence of other] orlah.
What is implied? 200 se'ah of orlah or mixed species from a vineyard fall into 40,000 se'ah of ordinary produce.41The prohibition is thus nullified because the ratio of permitted to forbidden substances is 200:1.
The Ra'avad criticizes the Rambam, questioning why he uses extremely large numbers. The Radbaz explains that the Rambam's figures enable all the calculations to be made without fragments.
Afterwards,42I.e., after it was discovered that the forbidden substance had fallen into the permitted substances. See the Rambam's Commentary to the Mishnah (Terumot 5:8). a se'ah of orlah or mixed species from a vineyard fell into each of the 200 se'ah of orlah or mixed species from a vineyard, the entire mixture is permitted. Since the presence of the forbidden substance that fell into [the mixture] originally was nullified, the entire [mixture] is considered as ordinary produce that is permitted.43Thus despite the fact that it contains produce that was originally forbidden, the entire quantity may be used to nullify the presence of the second measure of forbidden produce that falls in.
The rationale for this leniency is that according to Scriptural Law, the entire measure is permitted when there is a simple majority of forbidden substances.

הלכה כ
בֶּגֶד שֶׁצְּבָעוֹ בִּקְלִפֵּי עָרְלָה יִשָּׂרֵף. נִתְעָרֵב בַּאֲחֵרִים יַעֲלֶה בְּאֶחָד וּמָאתַיִם. וְכֵן תַּבְשִׁיל שֶׁבִּשְּׁלוֹ בִּקְלִפֵּי עָרְלָה וּפַת שֶׁאֲפָאָהּ בִּקְלִפֵּי עָרְלָה אוֹ בְּכִלְאֵי הַכֶּרֶם יִשָּׂרֵף הַתַּבְשִׁיל וְהַפַּת. שֶׁהֲרֵי הֲנָיָתוֹ נִכֶּרֶת בָּהֶן. נִתְעָרְבוּ בַּאֲחֵרִים יַעֲלוּ בְּאֶחָד וּמָאתַיִם:
כסף משנה
20.
A garment that was dyed with shells of orlah44In his Commentary to the Mishnah (Orlah 1:8), the Rambam quotes the Sifra (Parshat Kedoshim) which teaches that since it is forbidden to benefit from Orlah, it is also forbidden to use it as a dye. The Rambam emphasizes that, accordingly, this applies, not only to fruit which is orlah, but also to the shells from which dye is made. In his notes to the Rambam's Commentary to the Mishnah, Rav Kapach cites a responsa from the Rambam from which it appears that this applies only to shells because they serve a fruit. It is not forbidden to make dye from the wood or the bark of a tree that is orlah. See Halachah 24 and notes. should be burnt.45Since the substance from which the dye comes is forbidden, the entire article becomes forbidden. If it became intermingled with others, [its presence] may be nullified when there are 201 times the original amount.46The Rambam's wording - and hence, our translation - implies that one may cause the presence of the forbidden garment to be nullified by adding 200 other garments to it. The Radbaz explains that the mixture is forbidden only according to Rabbinic Law. As stated in Chapter 15, Halachah 26, as an initial and preferred option, one may add a sufficient quantity of permitted substances to nullify the presence of a substance forbidden by Rabbinic Law. Note, however, the glosses of the Tosafot Yom Tov and Rav Kapach to Orlah 3:1, that do not accept this interpretation and state that one may not nullify the prohibition as an initial and preferred option. Similarly, when a dish was cooked or a loaf of bread baked with the shells of orlah or mixed species from a vineyard, the dish or the bread must be burnt, for the benefit [from the forbidden substance] is evident.47See Halachah 22. If it became intermingled with others, [its presence] may be nullified when there are 201 times the original amount.

הלכה כא
וְכֵן בֶּגֶד שֶׁאָרַג בּוֹ מְלֹא הַסִּיט שֶׁצְּבָעוֹ בָּעָרְלָה וְאֵין יָדוּעַ אֵי זֶה הוּא יַעֲלֶה בְּאֶחָד וּמָאתַיִם. נִתְעָרְבוּ סַמָּנֵי עָרְלָה בְּסַמָּנֵי הֶתֵּר יַעֲלוּ בְּאֶחָד וּמָאתַיִם. מֵי צֶבַע בְּמֵי צֶבַע יִבָּטֵל בְּרֹב:
כסף משנה
21.
Similarly, when milo hasit48In his notes to the Rambam's Commentary to the Mishnah (Orlah 3:2), Rav Kapach elaborates on the definition of this term, concluding that it is equal to two thumbbreadths. This is also reflected in the Rambam's ruling, Hilchot Shabbat 9:18. of a garment was dyed with [a dye that is] orlah, and [that garment] cannot be identified, [its presence] may be nullified when there are 201 times the original amount.49I.e., if the entire garment is not 201 times the size of the portion dyed with the forbidden dye. In his Commentary to the Mishnah, the Rambam explains that this law teaches us that if even a small portion of a garment is dyed with forbidden dye, the entire garment may become forbidden. If powdered dye that is orlah becomes mixed with powdered dye that is permitted, [its presence] may be nullified when there are 201 times the original amount. When liquid dye that is orlah becomes mixed with liquid dye that is permitted, its presence is nullified when there is a majority [of the permitted substance].50The Radbaz explains that a more lenient ruling is issued in this instance, because:
a) Here there is no substance that is forbidden, it is only the color that comes from the forbidden dye that is problematic. A differentiation can be made between this instance and the previous laws, for in those instances, the forbidden dye has already become permanently associated with a substance.
b) In this instance, the majority of the dyeing will result from the permitted dye. The effect of the prohibited dye is secondary.

הלכה כב
תַּנּוּר שֶׁהִסִּיקוֹ בִּקְלִפֵּי עָרְלָה וּבְכִלְאֵי הַכֶּרֶם בֵּין חָדָשׁ בֵּין יָשָׁן יוּצַן. וְאַחַר כָּךְ יָחֵם אוֹתוֹ בַּעֲצֵי הֶתֵּר. וְאִם בִּשֵּׁל בּוֹ קֹדֶם שֶׁיּוּצַן בֵּין פַּת בֵּין תַּבְשִׁיל הֲרֵי זֶה אָסוּר בַּהֲנָיָה. יֵשׁ שֶׁבַח עֲצֵי אִסּוּר בְּפַת אוֹ בְּתַבְשִׁיל. גָּרַף אֶת כָּל הָאֵשׁ וְאַחַר כָּךְ בִּשֵּׁל אוֹ אָפָה בְּחֻמּוֹ שֶׁל תַּנּוּר הֲרֵי זֶה מֻתָּר שֶׁהֲרֵי עֲצֵי אִסּוּר הָלְכוּ לָהֶן:
כסף משנה
22.
When an oven has been heated with shells of orlah or mixed species from a vineyard, it must be cooled off [before cooking in it]. [This applies] to both a new and an old [oven]. Afterwards, one should heat [the oven] with permitted wood.51If so, it is then permitted to use even a new oven. Heating a new oven with the shells of orlah completes the task of fashioning the oven. Thus there is reason to say that since it was completed in a forbidden manner, the oven itself would be forbidden. Nevertheless, when permitted fuel is used even for such an oven, the products are permitted. The rationale is that they are produced by two substances: the oven which is forbidden and the fuel which is permitted. Whenever there are two factors involved, one permitted and one forbidden, the result is permitted to be used (Pesachim 26b). We do not require the oven to be destroyed, for the oven is not inherently forbidden (Kessef Mishneh).
One might ask: If so, why is an oven that is heated with shells that are orlah forbidden to be used. Here also there are two factors involved, the oven which is permitted and the fuel which is forbidden. It is possible to explain that the leniency of allowing to use the yield produced by a forbidden and a permitted substance only after the fact. In this instance, cooling the oven provides an easy alternative (Radbaz).
If one cooked in it before it was cooled, whether bread or food, it is forbidden to benefit from it. [The rationale is that] the forbidden wood increased the value of the bread or the food.52One might ask, since the oven is permitted, even though the fuel is forbidden, there is both a permitted and a forbidden factor producing this result. Why, then, is the food forbidden? It is possible to explain that since the fire which is forbidden is evident and apparent, we rule stringently (Radbaz, Kessef Mishneh).
If one removed the entire fire53As indicated by the Halachah 24, this applies even if there are still glowing coals in the oven. and then cooked or baked with the heat of the oven [that remained], it is permitted, for the forbidden wood is no longer present.54One might ask: In the case of a new oven, since both factors - the oven and the fuel - are forbidden. Nevertheless, it appears that according to the Rambam, removing the fire is sufficient for the food to be permitted. For the oven itself is not inherently forbidden, it was only completed in a forbidden manner (Kessef Mishneh).

הלכה כג
קְעָרוֹת וְכוֹסוֹת וּקְדֵרוֹת וּצְלוֹחִיּוֹת שֶׁבִּשְּׁלָן הַיּוֹצֵר בִּקְלִפֵּי עָרְלָה הֲרֵי אֵלּוּ אֲסוּרִין בַּהֲנָאָה. שֶׁהֲרֵי דָּבָר הָאָסוּר בַּהֲנָאָה עָשָׂה אוֹתָן חָדָשׁ:
כסף משנה
23.
It is forbidden to benefit from plates, cups, pots, and bottles that were fired by a potter with shells of orlah. [The rationale is] they are made new by an object from which it is forbidden to benefit.55Since the fuel used to fire the kitchenware is the primary element in completing them, they are forbidden. The Turei Zahav 142:7 explains that here we are speaking about kitchenware on which food is served cold. Since the kitchenware was made in a forbidden manner, it is forbidden to benefit from it. If, however, a pot was fired with forbidden fuel and then used to cook kosher food, that food would be permitted as is the law concerning a new oven. The Meiri (in his gloss to Pesachim 26b), however, explains that if one cooks food with a pot forbidden because of these factors, the food is forbidden.

הלכה כד
פַּת שֶׁבִּשְּׁלָהּ עַל גַּבֵּי גֶּחָלִים שֶׁל עֲצֵי עָרְלָה מֻתֶּרֶת. כֵּיוָן שֶׁנַּעֲשׂוּ גֶּחָלִים הָלַךְ אִסּוּרָן אַף עַל פִּי שֶׁהֵן בּוֹעֲרוֹת. קְדֵרָה שֶׁבִּשֵּׁל אוֹתָהּ בִּקְלִפֵּי עָרְלָה אוֹ בְּכִלְאֵי הַכֶּרֶם וּבַעֲצֵי הֶתֵּר הֲרֵי הַתַּבְשִׁיל אָסוּר. וְאַף עַל פִּי שֶׁזֶּה וְזֶה גּוֹרֵם. שֶׁבְּשָׁעָה שֶׁנִּתְבַּשְּׁלָה מֵחֲמַת עֲצֵי אִסּוּר עֲדַיִן לֹא בָּאוּ עֲצֵי הַהֶתֵּר וְנִמְצָא מִקְצָת הַבִּשּׁוּל בַּעֲצֵי הֶתֵּר וּמִקְצָתוֹ בְּאִסּוּר:
כסף משנה
24.
When bread was baked on coals from wood56The Radbaz emphasizes that here, too, we are speaking about shells from fruit that is orlah. The wood of a tree never becomes forbidden as orlah. that is orlah, it is permitted. Once [the wood] becomes coals, the forbidden dimension is no longer present, even though they are still glowing.57For once the wood is consumed by fire, it is no longer considered forbidden. See Hilchot Pesulei HaMukdashim 19:13 which states that it is permitted to benefit from the ashes of substances that are forbidden and required to be burnt.
When a pot was cooked with shells from orlah or mixed species from a vineyard together with permitted wood,58As evident from the continuation of the Rambam's statements, this applies when the permitted fuel was added after the forbidden fuel. Implied is that were the two fuels mixed together at the outset, the dish would be permitted. the food [cooked in it] is forbidden, even though [it was cooked by two factors, one forbidden and one permitted]. [The rationale is] that at the time it was cooked with the forbidden wood, the permitted wood had not been introduced. Thus part of the cooking process was performed with permitted wood and part with forbidden wood.59The Kessef Mishneh gives two interpretations for this halachah. Our translation follows the first interpretation. The Kessef Mishneh, however, questions that interpretation, stating that seemingly, the fact that the pot in which the food was cooked was permitted would add another permitted factor and thus the food was never cooked in a totally forbidden setting. He therefore offers another interpretation, stating that here the Rambam is speaking about firing the pot in which the food was cooked. First it was fired with forbidden fuel, then it was fired with permitted fuel, and then food was cooked in it with permitted fuel. Since it was originally fired with forbidden fuel, it becomes forbidden and any food cooked in it is likewise prohibited. The Turei Zahav 142:9 favors the first interpretation, explaining that the situation resembles food cooked in an oven with forbidden fuel.

הלכה כה
נְטִיעָה שֶׁל עָרְלָה שֶׁנִּתְעָרְבָה בִּנְטִיעוֹת. וְכֵן עֲרוּגָה שֶׁל כִּלְאֵי הַכֶּרֶם בַּעֲרוּגוֹת. הֲרֵי זֶה לוֹקֵט לְכַתְּחִלָּה מִן הַכּל. וְאִם הָיְתָה נְטִיעָה בְּמָאתַיִם נְטִיעוֹת וַעֲרוּגָה בְּמָאתַיִם עֲרוּגוֹת הֲרֵי כָּל הַנִּלְקָט מֻתָּר. וְאִם הָיוּ בְּפָחוֹת מִזֶּה כָּל הַנִּלְקָט אָסוּר. וְלָמָּה הִתִּירוּ לוֹ לִלְקֹט לְכַתְּחִלָּה וְהָיָה מִן הַדִּין שֶׁאוֹסְרִין לוֹ הַכּל עַד שֶׁיִּטְרַח וְיוֹצִיא הַנְּטִיעָה וְהָעֲרוּגָה הָאֲסוּרָה. שֶׁהַדָּבָר חֲזָקָה שֶׁאֵין אָדָם אוֹסֵר כַּרְמוֹ בִּנְטִיעָה אַחַת וְאִלּוּ הָיָה יוֹדְעָהּ הָיָה מוֹצִיאָהּ:
כסף משנה
25.
When a plant that is orlah becomes mixed together with other plants or a row of mixed species from a vineyard became mixed with other rows,60I.e., it was known that one plant or row was forbidden, but one was not able to identify the forbidden plant. It is somewhat difficult to conceive how a row of crops could not be recognized as mixed species growing in a vineyard. at the outset, one should gather all [the produce].61Significantly, in his Commentary to the Mishnah (Orlah 1:6), the Rambam rules that at the outset, it is forbidden to gather this produce. The leniency stated in this halachah applies only after the fact. The Kessef Mishneh states that the Rambam changed his mind, because the more lenient opinion is mentioned in the Talmud (Gittin 54b). If [the ratio of] permitted plants to forbidden plants was 200:1 or the ratio of forbidden rows to permitted ones is 200:1, everything that was gathered is permitted. If the ratio was less than this, all that was gathered is forbidden.
[One might ask:] Why is one permitted to gather [the produce] at the outset? Seemingly, the law should require that everything be forbidden for him until he undertakes the difficulty of removing the forbidden plant or row.62I.e., perhaps we should ordain a decree, forbidding benefit from the entire field, lest one intentionally mix a forbidden orlah plant into his vineyard. [It can be explained that that] a person will not cause his vineyard to be forbidden because of one plant.63Hence we do not fear that he will introduce a forbidden plant into the vineyard. Were he to be able to identify it, he would remove it.64I.e., we do not fear that he left the orlah plant intentionally.
In Hilchot Terumot 13:12, the Rambam rules more stringently with regard to terumah. A distinction between the two instances can be made, for terumah may be eaten by priests, while orlah is forbidden to everyone.

הלכה כו
הַמַּעֲמִיד גְּבִינָה בִּשְׂרַף פַּגֵּי עָרְלָה. אוֹ בְּקֵיבַת תִּקְרֹבֶת עַכּוּ''ם. אוֹ בְּחֹמֶץ יַיִן שֶׁל עַכּוּ''ם. הֲרֵי זוֹ אֲסוּרָה בַּהֲנָיָה אַף עַל פִּי שֶׁהוּא מִין בְּשֶׁאֵינוֹ מִינוֹ וְאַף עַל פִּי שֶׁהוּא כָּל שֶׁהוּא. שֶׁהֲרֵי הַדָּבָר הָאָסוּר הוּא הַנִּכָּר וְהוּא שֶׁעָשָׂה אוֹתָהּ גְּבִינָה:
כסף משנה
26.
It is forbidden to benefit from cheese that is made to harden using the syrup of orlah fruit that has not ripened,65In his Commentary to the Mishnah (Orlah 1:7), the Rambam states that it is common to use the white syrup that drips from underdeveloped figs as a catalyst to cause cheese to harden. the stomach66I.e., using the renin as a catalyst. of an animal offered as a sacrifice to false divinities, or vinegar made from the wine of a false divinity. Although the forbidden entity is being mixed with a substance of another type and a very small amount is used, [the cheese] is forbidden for [the effect of] the forbidden entity is obvious, for it [caused the milk] to harden into cheese.67See Chapter 3, Halachah 13. In his Commentary to the Mishnah (Avodah Zarah 2:5), the Rambam writes that the laws applying to a catalyst used to make cheese are more severe than those applying to spices and yeast (Halachah 1, for the latter can be nullified when they fall into a substance of another type) for the reason explained above. As the Radbaz explains, even without yeast a dough would be able to be baked and a dish could be served without spices, but without a catalyst, milk would never harden into cheese.

הלכה כז
הָעָרְלָה וְכִלְאֵי הַכֶּרֶם דִּין הַפֵּרוֹת שֶׁלָּהֶן שֶׁיִּשָּׂרְפוּ. וְהַמַּשְׁקִין שֶׁלָּהֶן יִקָּבְרוּ מִפְּנֵי שֶׁאִי אֶפְשָׁר לִשְׂרֹף הַמַּשְׁקִין:
כסף משנה
27.
The law is that fruit that is orlah or from mixed species from a vineyard should be burnt.68Kiddushin 56b derives this from the exegesis of Deuteronomy 22:9, pen tikadeish, "lest it become hallowed," interpreting it as pen tukad eish, "lest it be consigned to fire." Liquids from [that fruit] should be buried, because it is impossible to burn liquids.

הלכה כח
יַיִן שֶׁנִּתְנַסֵּךְ לְעַכּוּ''ם שֶׁנִּתְעָרֵב עִם הַיַּיִן הַכּל אָסוּר בַּהֲנָיָה בְּכָל שֶׁהוּא כְּמוֹ שֶׁאָמַרְנוּ. בַּמֶּה דְּבָרִים אֲמוּרִים בְּשֶׁהוּרַק הַיַּיִן הַמֻּתָּר עַל טִפָּה שֶׁל יֵין נֶסֶךְ. אֲבָל אִם עֵרָה יֵין נֶסֶךְ מִצִּלְצוּל קָטָן לְתוֹךְ הַבּוֹר שֶׁל יַיִן. אֲפִלּוּ עֵרָה כָּל הַיּוֹם כֻּלּוֹ רִאשׁוֹן רִאשׁוֹן בָּטֵל. עֵרָה מִן הֶחָבִית בֵּין שֶׁעֵרָה מִן הַמֻּתָּר לָאָסוּר אוֹ מִן הָאָסוּר לַמֻּתָּר הַכּל אָסוּר מִפְּנֵי שֶׁהָעַמּוּד הַיּוֹרֵד מִפִּי הֶחָבִית גָּדוֹל:
כסף משנה
28.
When wine that was poured as a libation to idols is mixed with [other] wine, it is forbidden to benefit from the entire mixture regardless of how small [the amount of forbidden wine], as we explained.69Chapter 15, Halachot 6-7.
When does the above apply? When the permitted wine is poured onto a drop of wine that had been poured as a libation.70The Siftei Cohen quotes Rishonim who rule that if a quantity of permitted wine that is 60 times the volume of the forbidden wine falls into the forbidden wine at the same time, the presence of the forbidden wine is nullified. The stringency mentioned by the Rambam applies only when the kosher wine is poured into the forbidden wine little by little. The Siftei Cohen rules that if a severe loss is involved, one may rely on this leniency. If, however, one poured wine that had been poured as a libation from a small bottle71I.e., a bottle from which the wine is poured one drop at a time. into a cistern of wine, its presence is nullified. Even if one poured the entire day, each individual drop becomes nullified, drop after drop.72The Radbaz states that this applies even if the majority of the mixture comes from the forbidden wine. Since each drop was nullified, the entire quantity is permitted. The Siftei Cohen 134:4 differs and requires that the permitted wine be 60 times the volume of the forbidden wine.
According to the Rambam, it is even permitted to drink the wine of the mixture. Rashi (Avodah Zarah 73a) rules that it is permitted to benefit from the wine, drinking it, however, is forbidden. And the Ra'avad rules that it is forbidden even to benefit from it. The Shulchan Aruch (Yoreh De'ah 134:1) quotes the Rambam's ruling.

If one pours from a jug,73I.e., a container with a large opening. the entire quantity is forbidden. [This applies] whether one pours permitted wine into forbidden wine or forbidden wine into permitted wine. [This stringency is enforced,] because the column of wine which descends from the large jug [creates a connection].

הלכה כט
נִתְעָרֵב סְתָם יֵינָם בַּיַּיִן הֲרֵי זֶה אָסוּר בְּכָל שֶׁהוּא בִּשְׁתִיָּה וְיִמָּכֵר כֻּלּוֹ לְעַכּוּ''ם. וְלוֹקֵחַ דְּמֵי הַיַּיִן הָאָסוּר שֶׁבּוֹ וּמַשְׁלִיכוֹ לְיָם הַמֶּלַח וְיֵהָנֶה בִּשְׁאָר הַמָּעוֹת. וְכֵן אִם נִתְעָרְבָה חָבִית שֶׁל יֵין נֶסֶךְ בֵּין הֶחָבִיּוֹת הַכּל אֲסוּרִין בִּשְׁתִיָּה וּמֻתָּרִין בַּהֲנָיָה. וְיוֹלִיךְ דְּמֵי אוֹתָהּ חָבִית לְיָם הַמֶּלַח כְּשֶׁיִּמְכֹּר הַכּל לְעַכּוּ''ם. וְכֵן בְּחָבִית שֶׁל סְתָם יֵינָם:
כסף משנה
29.
When even the smallest amount of ordinary [gentile] wine is mixed with [Jewish] wine, it is forbidden to drink [the entire mixture].74The Rama (Yoreh De'ah 134:2) rules leniently, stating that in the present era, since it is no longer customary to pour wine as libations to false divinities, one may be lenient and permit the mixture if there is 60 times more kosher wine than forbidden wine, provided the kosher wine is not poured into the forbidden wine in one column. Instead, it should be sold to a gentile in its entirety. The money [paid] for the forbidden wine should be cast into the Dead Sea.75I.e., cast into a place where one will not benefit from it. One may, however, benefit from the remainder of the money.76One may, however, destroy one jug and then benefit from the others - e.g., to use the wine as a dye - for it is possible that one will be benefiting directly from the forbidden wine. The advice suggested by the Rambam, by contrast, allows the Jew to benefit from the remainder of the wine without any possibility of benefiting directly from the forbidden wine.
The advice suggested applies only to jugs, for each jug is a separate entity. It does not apply when wine becomes mixed with wine, as indicated by the previous halachah (Avodah Zarah 74a).

Similarly, if a jug of wine poured as a libation had become intermingled with jugs of [kosher] wine, it is forbidden to drink the entire mixture.77See the Rama (Yoreh De'ah 134:2) who explains that this applies only when the jugs are large and therefore important as mentioned in Halachah 3. Otherwise, the presence of the forbidden jug can be nullified by a simple majority. One may, however, benefit from it, selling the entire mixture to a gentile and casting the money for the [forbidden] jug into the Dead Sea. The same applies with regard to a jug of ordinary [gentile] wine.78Seemingly, this ruling is obvious. The Kessef Mishneh states that it was added to emphasize the stringency that one must destroy the value of the forbidden jug.

הלכה ל
מַיִם שֶׁנִּתְעָרְבוּ בְּיַיִן אוֹ יַיִן בְּמַיִם בְּנוֹתֵן טַעַם מִפְּנֵי שֶׁהֵן מִין בְּשֶׁאֵינוֹ מִינוֹ. בַּמֶּה דְּבָרִים אֲמוּרִים בְּשֶׁנָּפַל הַמַּשְׁקֶה הַמֻּתָּר לְתוֹךְ הַמַּשְׁקֶה הָאָסוּר. אֲבָל אִם נָפַל הַמַּשְׁקֶה הָאָסוּר לְתוֹךְ הַמַּשְׁקֶה הַמֻּתָּר רִאשׁוֹן רִאשׁוֹן בָּטֵל. וְהוּא שֶׁיּוּרַק מִצִּלְצוּל קָטָן שֶׁהָיָה מֵרִיק וְיוֹרֵד מְעַט מְעַט. וְהֵיאַךְ יִהְיוּ הַמַּיִם אֲסוּרִים כְּגוֹן שֶׁהָיוּ נֶעֱבָדִין אוֹ תִּקְרֹבֶת עַכּוּ''ם:
כסף משנה
30.
When water is mixed into wine or wine is mixed into water, [the forbidden entity causes the mixture to be prohibited] if its flavor can be detected, because they are two different types of substances.79As stated in Chapter 15, Halachah 6.
When does the above apply? When the permitted liquid falls into the forbidden liquid. If, however, the forbidden liquid fell into the permitted liquid, the presence of it is nullified, drop after drop, provided it fell from a from a small bottle.80See Halachah 28.
Rav Moshe HaCohen questions how the presence of the forbidden entity can be nullified, since its flavor can be detected. Indeed, when quoting this law, Shulchan Aruch (Yoreh De'ah 134:3) states this leniency applies only when the taste of the forbidden substance cannot be detected.

How is it possible for water to be forbidden? If it was worshipped or if it was offered to a false divinity.

הלכה לא
בּוֹר שֶׁל יַיִן שֶׁנָּפַל לְתוֹכוֹ קִיתוֹן שֶׁל מַיִם תְּחִלָּה וְאַחַר כָּךְ נָפַל לְתוֹכוֹ יֵין נֶסֶךְ. רוֹאִים אֶת יֵין הַהֶתֵּר כְּאִלּוּ אֵינוֹ וְהַמַּיִם שֶׁנָּפְלוּ מְשַׁעֲרִין בָּהֶן עִם יֵין נֶסֶךְ. אִם רְאוּיִין לְבַטֵּל טַעַם אוֹתוֹ יֵין נֶסֶךְ הֲרֵי הַמַּיִם רָבִין עָלָיו וּמְבַטְּלִין אוֹתוֹ וְיִהְיֶה הַכּל מֻתָּר:
כסף משנה
31.
[The following law applies when] a pitcher of water fell into a cistern of wine and afterwards,81Avodah Zarah 73a emphasizes that the leniency mentioned in this halachah applies only when the water falls into the wine before the forbidden wine. If the forbidden wine falls in first, the permitted wine becomes prohibited. wine that was poured as a libation fell into it. [Initially,] we consider the permitted wine as if it did not exist,82And thus it is not automatically forbidden. We measure the water in relation to the wine poured as a libation. If it83I.e., the water alone. The permitted wine is not considered, for any amount of the forbidden wine mixed into it would cause the permitted wine to be prohibited. is [of sufficient volume] to nullify the taste of the wine poured as a libation, the water is more abundant than it and it nullifies [the forbidden wine] and the entire [mixture] is permitted.

הלכה לב
יֵין נֶסֶךְ שֶׁנָּפַל עַל הָעֲנָבִים יְדִיחֵם וְהֵן מֻתָּרוֹת בַּאֲכִילָה. וְאִם הָיוּ מְבֻקָּעוֹת בֵּין שֶׁהָיָה הַיַּיִן יָשָׁן בֵּין שֶׁהָיָה חָדָשׁ אִם נוֹתֵן טַעַם בָּעֲנָבִים הֲרֵי אֵלּוּ אֲסוּרוֹת בַּהֲנָיָה. וְאִם לָאו הֲרֵי אֵלּוּ מֻתָּרוֹת בַּאֲכִילָה:
כסף משנה
32.
When wine poured as a libation falls on grapes, one should wash them. They are permitted to be eaten.84For the forbidden wine will not have entered them. If the grapes have split open,85And thus the forbidden wine could enter. when the wine imparts its flavor to them, it is forbidden to benefit from them.86They may, however, be sold to a gentile, minus the increase in their value produced by the forbidden wine [Shulchan Aruch (Yoreh De'ah 134:8)].If not, it is permitted to partake of them. [This applies] whether the wine is aged or fresh.87Avodah Zarah 66a emphasizes that even if the fresh wine has the same flavor as the grapes, the grapes are not forbidden. For the wine is considered as a different type of substance.

הלכה לג
נָפַל עַל גַּבֵּי תְּאֵנִים הֲרֵי אֵלּוּ מֻתָּרוֹת מִפְּנֵי שֶׁהַיַּיִן פּוֹגֵם בְּטַעַם הַתְּאֵנִים:
כסף משנה
33.
When [forbidden wine] falls on figs, they are permitted, because wine impairs the flavor of figs.88Hence even if it imparts its flavor, the figs are not forbidden. Although the version of Avodah Zarah 5:2 which the Rambam relies on differs from the standard published text of the Mishnah, the Rambam's ruling is accepted as halachah by Shulchan Aruch (Yoreh De'ah134:9).

הלכה לד
יֵין נֶסֶךְ שֶׁנָּפַל עַל הַחִטִּים הֲרֵי אֵלּוּ אֲסוּרוֹת בַּאֲכִילָה וּמֻתָּרוֹת בַּהֲנָיָה. וְלֹא יִמְכְּרֵם לְעַכּוּ''ם שֶׁמָּא יַחֲזֹר וְיִמְכְּרֵם לְיִשְׂרָאֵל. אֶלָּא כֵּיצַד עוֹשֶׂה. טוֹחֵן אוֹתָן וְעוֹשֶׂה מֵהֶן פַּת וּמוֹכְרָהּ לְעַכּוּ''ם שֶׁלֹּא בִּפְנֵי יִשְׂרָאֵל כְּדֵי שֶׁלֹּא יִקְּחוּ אוֹתָהּ יִשְׂרָאֵל מִן הָעַכּוּ''ם שֶׁהֲרֵי פַּת עַכּוּ''ם אֲסוּרָה כְּמוֹ שֶׁיִּתְבָּאֵר. וְלָמָּה אֵין בּוֹדְקִין אֶת הַחִטִּים בְּנוֹתֵן טַעַם מִפְּנֵי שֶׁהֵן שׁוֹאֲבוֹת וְהַיַּיִן נִבְלָע בָּהֶן:
כסף משנה
34.
When wine poured as a libation falls on wheat, [the wheat] is forbidden to be eaten, but it is permitted to benefit from it. One should not sell it to a gentile, lest he sell it again to a Jew. What should be done instead? He should grind [the wheat] into flour, make it into bread, and sell it to a gentile outside the presence of a Jew.89This is permitted, for the gentile is paying for the bread alone. He is not paying for the wine at all. [In this way,] a Jew will not repurchase it from the gentile,90If, however, the Jew selling a fellow Jew selling bread to the gentile, he might purchase it from him. for the bread of a gentile is forbidden, as will be explained.91Chapter 17, Halachah 9. A Jew will have no way of knowing that this bread was not baked by the gentile. Hence he will refrain from purchasing it from him. In a place where it is customary to purchase bread from gentiles, there is no way of benefiting from the wheat [Shulchan Aruch (Yoreh De'ah 134:11)].
Why do we not check the wheat to see if [the wine imparted] its flavor? Because [the wheat] draws out the wine92As Avodah Zarah 65b states, the kernels of wheat are cracked and this causes them to absorb the wine (Lechem Mishneh; Shulchan Aruch, loc. cit.). and it becomes absorbed within it.93The Radbaz emphasizes that the taste of the wine becomes blended in with the taste of the wheat to the extent that it cannot be detected.

הלכה לה
יֵין נֶסֶךְ שֶׁהֶחֱמִיץ וְנָפַל לְתוֹךְ חֹמֶץ שֵׁכָר אוֹסֵר בְּכָל שֶׁהוּא מִפְּנֵי שֶׁהוּא בְּמִינוֹ שֶׁשְּׁנֵיהֶן חֹמֶץ הֵן. וְיַיִן שֶׁנִּתְעָרֵב עִם הַחֹמֶץ בֵּין שֶׁנָּפַל חֹמֶץ לַיַּיִן בֵּין שֶׁנָּפַל יַיִן לַחֹמֶץ מְשַׁעֲרִין אוֹתוֹ בְּנוֹתֵן טַעַם:
כסף משנה
35.
When wine poured as a libation becomes vinegar94The vinegar is forbidden, as the wine was. and falls into vinegar that comes from beer, even the slightest amount causes it to become forbidden. [The rationale is that] it is considered to have become mixed with the same type of substance, because they are both vinegar.95The fact that originally one was wine and one was beer is not significant.
When wine becomes mixed with vinegar, we see if [the forbidden entity] imparts its flavor.96If it does, the mixture is forbidden. If not, it is permitted. Even if the vinegar originally came from wine, it is considered as a different substance. [This applies] whether [forbidden] vinegar falls into wine97It is not automatically permitted, because vinegar impairs the flavor of wine, for there are some who prefer vinegar to wine (Rashba, as quoted by Turei Zahav 134:8). or [forbidden] wine falls into vinegar.

קדושה הלכות מאכלות אסורות פרק טז
Kedushah Ma`akhalos Assuros Chapter 16