Halacha
הלכה א
בִּימֵי יוֹחָנָן כֹּהֵן גָּדוֹל שֶׁהָיָה אַחַר שִׁמְעוֹן הַצַּדִּיק שָׁלְחוּ בֵּית דִּין הַגָּדוֹל וּבָדְקוּ בְּכָל גְּבוּל יִשְׂרָאֵל וּמָצְאוּ שֶׁהַכּל זְהִירִים בִּתְרוּמָה גְּדוֹלָה וּמַפְרִישִׁין אוֹתָהּ. אֲבָל מַעֲשֵׂר רִאשׁוֹן וּמַעֲשֵׂר שֵׁנִי וּמַעֲשַׂר עָנִי הָיוּ עַמֵּי הָאָרֶץ מִיִּשְׂרָאֵל מְקִלִּין עַל עַצְמָן וְלֹא הָיוּ מַפְרִישִׁין אוֹתָן. לְפִיכָךְ גָּזְרוּ שֶׁלֹּא יְהֵא נֶאֱמָן עַל הַמַּעַשְׂרוֹת אֶלָּא אֲנָשִׁים נֶאֱמָנִים. אֲבָל עַמֵּי הָאָרֶץ פֵּרוֹתֵיהֶן סָפֵק וְאֵין נֶאֱמָנִין לוֹמַר מְעֵשָּׂרִין הֵן. וְזֶהוּ הַנִּקְרָא דְּמַאי:
כסף משנה
1.
In the age of Yochanan the High Priest who served after Shimon the Just,1I.e., not the Hasmonean High Priest of that name who became a Sadducee (Kessef Mishneh). the High Court sent emissaries who searched throughout the entire territory of Israel. They discovered that everyone was careful with regard to the great terumah2Since it is punishable by death at the hand of heaven, people were meticulous in separating it [the Rambam's Commentary to the Mishnah (Demai 1:1). and would separate it. But with regard to the first tithe, the second tithe, and the tithe for the poor, the common people among Israel would be lax and would not separate it.3The majority of the common people would separate the tithes as well. Nevertheless, because there was a significant minority who did not, our Sages imposed this stringency. Therefore [the Sages] decreed that only the word of trustworthy people4See Chapter 10, Halachot 1-2. would be relied upon with regard to tithes.5I.e., if such people say that their produce was tithed, we accept their word. [The status of the produce of] the common people, by contrast is doubtful. We do not rely on them if they say that they separated the tithes. This is called demai.6The name demai is a composite of the Aramaic words da mai, meaning "This, what is its status?" (Radbaz).See also Hilchot Berachot 1:20 which states that it is necessary to recite a blessing before partaking of demai. That indicates that although our Sages ordained that one should separate the tithes before partaking of it, they did not consider partaking of it an outright prohibition. For if so, reciting a blessing would not be in place.
הלכה ב
וְהִתְקִינוּ שֶׁלֹּא יְהֵא אָדָם מַפְרִישׁ מִן הַדְּמַאי אֶלָּא תְּרוּמַת מַעֲשֵׂר מִפְּנֵי שֶׁהוּא עֲוֹן מִיתָה. וּמַעֲשֵׂר שֵׁנִי שֶׁאֵין בָּזֶה הֶפְסֵד שֶׁהֲרֵי בְּעָלָיו אוֹכְלִין אוֹתוֹ. אֲבָל מַעֲשֵׂר רִאשׁוֹן וּמַעֲשַׂר עָנִי אֵין מַפְרִישׁ מִן הַדְּמַאי מִפְּנֵי שֶׁהוּא סָפֵק וְהַמּוֹצִיא מֵחֲבֵרוֹ עָלָיו הָרְאָיָה. לְפִיכָךְ אוֹמֵר לַלֵּוִי אוֹ לֶעָנִי הָבֵא רְאָיָה שֶׁאֵינוֹ מְעֵשָּׂר וְטֹל מַעַשְׂרוֹת:
כסף משנה
2.
They ordained that a person should separate only terumat ma'aser from the demai, for it is a transgression punishable by death and the second tithe, for there is no loss in doing so since the owner partakes of it. One need not, however, separate the first tithe or the tithe for the poor from demai because [the obligation] is doubtful and [whenever one desires] to expropriate property from a colleague, the burden of proof is on him. Therefore he tells the Levite or the poor person:7I.e., to whom these tithes would be given. "Bring proof that it is not tithed," and then take the tithes.הלכה ג
אַף עַל פִּי שֶׁאֵין מַפְרִישִׁין מַעֲשַׂר עָנִי מִן הַדְּמַאי צָרִיךְ לִקְרוֹת לוֹ שֵׁם וְאֵינוֹ מַפְרִישׁ וְאוֹמֵר עִשּׂוּר מַה שֶּׁיֵּשׁ כָּאן מַעֲשַׂר עָנִי כְּדֵי לִקְבֹּעַ מַעֲשֵׂר שֵׁנִי שֶׁמַּעֲשַׂר עָנִי בִּשְׁלִישִׁית וְשִׁשִּׁית בִּמְקוֹם מַעֲשֵׂר שֵׁנִי שֶׁל שְׁאָר שְׁנֵי הַשָּׁבוּעַ:
כסף משנה
3.
Even though one does not separate the tithe for the poor from demai, it is necessary to designate it without separating it. One says: "A tenth of what is here is the tithe for the poor. [This is done] to firmly establish [the obligation of] the second tithe.8I.e., the Sages ordained this stringency with regard to the tithe for the poor, so that the people will be careful in their observance of the second tithe. For the tithe for the poor is given in the third and sixth years instead of the second tithe given in the other years of the Sabbatical cycle.הלכה ד
כְּשֶׁמַּפְרִישִׁין מִן הַדְּמַאי תְּרוּמַת מַעֲשֵׂר וּמַעֲשֵׂר שֵׁנִי אֵין מְבָרְכִין עֲלֵיהֶן לְפִי שֶׁהוּא סָפֵק. לְפִיכָךְ מֻתָּר לְהַפְרִישׁ כְּשֶׁהוּא עֵרוֹם:
כסף משנה
4.
When terumat ma'aser and the second tithe are separated from demai, a blessing is not recited, because [the obligation was instituted because] of a doubt.9Although one's observance fulfills a decree of our Sages and blessings are recited for the observance of Rabbinic commandments, e.g., the recitation of Hallel, lighting Shabbat and Chanukah candles, washing hands, and the like, a blessing is not recited in this instance, because this obligation was instituted only because of doubt, not as a practice with inherent positive virtue. Therefore it is permitted to separate it when one is naked.10I.e., were a blessing required, one would be forbidden to separate it in such a state, because a blessing could not be recited [the Rambam's Commentary to the Mishnah (Demai 1:4)].הלכה ה
כֵּיצַד מְעַשְּׂרִין אֶת הַדְּמַאי. מַפְרִישׁ כְּדֵי תְּרוּמַת מַעֲשֵׂר שֶׁהוּא אֶחָד מִמֵּאָה מִן הַכּל וּמַנִּיחָהּ בְּצַד הַפֵּרוֹת וְאוֹמֵר זֶה מַעֲשֵׂר וּשְׁאָר מַעֲשֵׂר סָמוּךְ לוֹ. וְאַחַר כָּךְ אוֹמֵר זֶה שֶׁאָמַרְתִּי עָלָיו שֶׁהוּא מַעֲשֵׂר הֲרֵי הוּא תְּרוּמַת מַעֲשֵׂר עַל שְׁאָר הַמַּעֲשֵׂר הַסָּמוּךְ לוֹ. וְנוֹטֵל אוֹתָהּ וְנוֹתְנָהּ לַכֹּהֵן שֶׁאֵינוֹ רַשַּׁאי לְהַפְרִישׁ תְּרוּמַת מַעֲשֵׂר קֹדֶם הַמַּעֲשֵׂר לְכַתְּחִלָּה. וְאַחַר כָּךְ מַפְרִישׁ מַעֲשֵׂר שֵׁנִי:
כסף משנה
5.
How should tithes be separated from demai? One should set aside an amount equivalent to the measure of terumat ma'aser, i.e., one hundredth of the entire amount, and place it next to the produce and say: "This is the tithe as is the remainder of the tithes that are adjacent to it." He then says: "This [portion] which I [first] set aside as the tithes, is terumat ma'aser for the remainder of the tithes that are adjacent to it."11The Radbaz emphasizes that he need not set the remainder of the tithes aside. Indeed, he continues, doing so would be an indication that he should give this produce to the Levite. He then takes it and gives it to a priest.12As a present. There is reason to say that since the matter is one of doubt, one is not required to give it to the priest, but instead, could sell it to him, our Sages ordained that it be given away. See the commentaries to Sotah 48a. This order is required, because idealy, it is forbidden to separate terumat ma'aser before the tithes themselves.13See Hilchot Terumot 3:23. Afterwards, he should separate the second tithe.הלכה ו
וּמֻתָּר לְהַפְרִישׁ מַעֲשֵׂר שֵׁנִי קֹדֶם הָרִאשׁוֹן בִּדְמַאי. וְאִם רָצָה אוֹמֵר מַעֲשֵׂר שֵׁנִי שֶׁל פֵּרוֹת אֵלּוּ בִּצְפוֹנָם אוֹ בִּדְרוֹמָם וַהֲרֵי הוּא מְחֻלָּל עַל הַמָּעוֹת. וְכֵן הַלּוֹקֵחַ כִּכָּר מִן הַנַּחְתּוֹם מַפְרִישׁ מִמֶּנָּה כְּדֵי תְּרוּמַת מַעֲשֵׂר וְחַלָּה וְאוֹמֵר אֶחָד מִמֵּאָה מִמַּה שֶּׁיֵּשׁ כָּאן הֲרֵי הוּא מַעֲשֵׂר וּשְׁאָר מַעֲשֵׂר סָמוּךְ לוֹ וְזֶה שֶׁעָשִׂיתִי מַעֲשֵׂר עָשׂוּי תְּרוּמַת מַעֲשֵׂר עַל הַשְּׁאָר הַסָּמוּךְ לוֹ וְהַיֶּתֶר עַל אֶחָד מִמֵּאָה שֶׁיֵּשׁ בָּזֶה שֶׁהִפְרַשְׁתִּי הֲרֵי הוּא חַלָּה וּמַעֲשֵׂר שֵׁנִי בִּצְפוֹנָהּ אוֹ בִּדְרוֹמָהּ וַהֲרֵי הוּא מְחֻלָּל עַל הַמָּעוֹת וְאוֹכֵל:
כסף משנה
6.
It is permissible to set aside the second tithe before the first tithe [when tithing] demai.14Generally, the tithes must be separated in the appropriate order (ibid.). An exception is made with regard to demai, for the obligation to separate it is only a Rabbinic stringency (the Jerusalem Talmud, Demai 1:4). See also Hilchot Ma'aser Sheni 11:13. If one desires,15i.e., if rather than partaking of the produce in Jerusalem as is required with regard to the second tithe, he chooses to redeem it, transferring its holiness to money. That money should be taken to Jerusalem and used to purchase food there. See Hilchot Ma'aser Sheni, chs. 4-5. he should say: "The second tithe of this produce is located in the northern portion - or the southern portion - of the produce and its [holiness] is transferred to this money."16I.e., it is not necessary to actually take this produce to Jerusalem and partake of it as the second tithe. Instead, its holiness could be transferred to money and used to purchase food there.Similarly, a person who purchases a loaf of bread from a baker17I.e., a baker who is a common person in whose instance the precautions concerning demai must be taken. should separate18In his Commentary to the Mishnah (Demai 5:1), the Rambam states that one should separate this portion from the loaf. Instead, one should slice a piece from the loaf, without cutting the slice away entirely. The commentaries question whether this is the intent here or that here, the Rambam changed his mind and is speaking of a complete separation. from it the amount to be separated as terumat ma'aser and as challah,19As stated in Hilchot Bikkurim 5:1-2, before one is permitted to partake of bread, one must separate a portion as challah. According to Scriptural Law, there is no minimum amount required for this separation. According to the Rabbis, a private person must separate one twenty-fourth of the loaf and a baker one forty-eighth. In this instance, the latter amount should be separated together with one hundredth for terumat ma'aser. and say: "The one hundredth of [the total] that is here is [part of] the tithes as well as the remainder of the tithes that are next to it.20As in Halachah 5. May this portion that I set aside as tithes, serve as terumat ma'aser for the remainder of the tithes that are next to it. The remainder of what I set aside that exceeds one hundredth of the total is challah and the second tithe in its northern - or southern - portion, and its [holiness] is transferred to this money." He may then partake [of the bread].
הלכה ז
וְכֵן הַמַּזְמִין אֶת חֲבֵרוֹ שֶׁיֹּאכַל אֶצְלוֹ וְהוּא אֵינוֹ מַאֲמִינוֹ עַל הַמַּעַשְׂרוֹת אוֹמֵר מֵעֶרֶב שַׁבָּת מַה שֶּׁאֲנִי עָתִיד לְהַפְרִישׁ לְמָחָר הֲרֵי הוּא מַעֲשֵׂר וּשְׁאָר מַעֲשֵׂר סָמוּךְ לוֹ. וְזֶה שֶׁעָשִׂיתִי מַעֲשֵׂר עָשׂוּי תְּרוּמַת מַעֲשֵׂר עַל שְׁאָר הַסָּמוּךְ לוֹ וּמַעֲשֵׂר שֵׁנִי בִּצְפוֹנוֹ אוֹ בִּדְרוֹמוֹ וַהֲרֵי הוּא מְחֻלָּל עַל הַמָּעוֹת. מִפְּנֵי שֶׁמֻּתָּר לְאָדָם לְהַתְנוֹת תְּנָאִים אֵלּוּ עַל הַדְּמַאי אַף עַל פִּי שֶׁאֵינוֹ בִּרְשׁוּתוֹ. אֲבָל בְּוַדַּאי אֵינוֹ מַתְנֶה אֶלָּא עַל דָּבָר שֶׁבִּרְשׁוּתוֹ:
כסף משנה
7.
Similarly, if a person invites a colleague to dine with him [on the Sabbath]21When it is forbidden to separate tithes (Hilchot Shabbat 23:14). and [the guest] does not trust [the host] with regard to the separation of the tithes,22Although a person who is meticulous in his observance of the tithes should not eat in a common person's home (Chapter 10, Halachah 1), it can be explained that this is speaking about an instance where the person accepted the invitation without knowing that the host was not meticulous in his observance of the mitzvah. We are, however, speaking about a situation where the guest merely suspects that his host is not meticulous in his observance. If he is certain that he is not meticulous, different rules apply, as the Rambam states in the final clause of the halachah. The leniencies to follow were granted only for the sake of the Sabbath, but not during the week. [the guest should do the following]: On Friday, he should say: "[The produce] that I will separate tomorrow is [part of] the tithes, as is the remainder of the tithes which are adjacent to it. That portion which I [first] designated as the tithes is terumat ma'aser for the remainder which is adjacent to it. The second tithe in its northern - or southern - portion, and its [holiness] is transferred to [this] money."[This is permitted,] because a person may make such stipulations with regard to demai even though it is not in his possession.23This leniency is granted because the obligation to make these separations is Rabbinic in origin. When, however, we are certain [that the tithes have not been separated,] he may make stipulations only concerning produce that is in his possession.
הלכה ח
כֵּיצַד. הָיוּ לוֹ מֵאָה תְּאֵנִים שֶׁל טֶבֶל בְּבֵיתוֹ וְהוּא בְּבֵית הַמִּדְרָשׁ אוֹ בַּשָּׂדֶה וּמִתְיָרֵא שֶׁמָּא תֶּחְשַׁךְ וְאֵינוֹ יָכוֹל לְעַשֵּׂר בְּשַׁבָּת אוֹמֵר שְׁנֵי תְּאֵנִים שֶׁאֲנִי עָתִיד לְהַפְרִישׁ הֲרֵי הֵן תְּרוּמָה. וְעֶשֶׂר שֶׁאֲנִי מַפְרִישׁ אַחֲרֵיהֶן מַעֲשֵׂר רִאשׁוֹן. תֵּשַׁע שֶׁאֲנִי מַפְרִישׁ אַחֲרֵיהֶן מַעֲשֵׂר שֵׁנִי. וּלְמָחָר מַפְרִישׁ וְאוֹכֵל:
כסף משנה
8.
What is implied?24I.e., how can a stipulation be made before the Sabbath for produce that we know is tevel to be tithed on the Sabbath? If, [on Friday,] he had 100 figs that were tevel in his home and he is in the house of study or in the field25And thus he cannot physically separate them before the onset of the Sabbath. and he is afraid that night will fall and he will not be able to tithe the produce on the Sabbath, he should say: "The two figs that I will separate are terumah. The ten that I will separate after them are the first tithe. And the nine that I will separate after them are the second tithe." On the morrow, he makes these separations and may then partake [of the figs].26He may not, however, partake of the figs and then leave the tithes. The rationale is that in questions of Scriptural Law, the principle of bereirah is not applied and we do not consider it as if the separation that he will ultimately make was made from the outset [the Rambam's Commentary to the Mishnah (Demai 7:5)]. See also Chapter 1, Halachah 9.הלכה ט
וְצָרִיךְ לִרְחשׁ בִּשְׂפָתָיו בְּשָׁעָה שֶׁמַּפְרִישׁ זוֹ אַחַר זוֹ וְאֵינוֹ כִּמְתַקֵּן בְּשַׁבָּת שֶׁהֲרֵי הִקְדִּים תְּנָאוֹ. וְטֶבֶל שֶׁיֵּשׁ עָלָיו תְּנַאי זֶה מֻתָּר לְטַלְטְלוֹ בְּשַׁבָּת קֹדֶם שֶׁיַּפְרִישׁ. וְנוֹתֵן עֵינָיו בְּצַד זֶה וְאוֹכֵל אֶת הַשְּׁאָר:
כסף משנה
9.
He must whisper inaudibly [the appropriate statements]27Stating that he had made a stipulation on the previous day. when he is making these separations one after the other. He is not considered as making an article fit for use on the Sabbath,28The reason it is forbidden to separate tithes on the Sabbath. because he made the stipulation previously.When such a stipulation has been made concerning tevel, it is permitted to move it on the Sabbath,29If, however, such a stipulation was not made before the onset of the Sabbath, it is forbidden to move the tevel. Since it is forbidden to partake of it on the Sabbath, it is comparable to a stone (Hilchot Shabbat 25:19). [even] before the separations were made.30Since after the separations will be made, it will be permitted to partake of it, one never diverted his attention from using it on the Sabbath. He should focus his attention on [a portion of the produce, designating it as terumah and tithes] and partake of the remainder.31Even if the tithes have not been taken away from the produce, since they have already been separated and their place is distinct, it is as if they have been separated already. We do not have to rely on the principle of bereirah (Radbaz).
הלכה י
נָתַן לוֹ עַם הָאָרֶץ כּוֹס לִשְׁתּוֹתוֹ אוֹמֵר מַה שֶּׁאֲנִי עָתִיד לְשַׁיֵּר בְּשׁוּלֵי הַכּוֹס הֲרֵי הוּא מַעֲשֵׂר וּשְׁאָר מַעֲשֵׂר סָמוּךְ לוֹ וְזֶה שֶׁעָשִׂיתִי מַעֲשֵׂר עָשׂוּי תְּרוּמַת מַעֲשֵׂר עַל הַשְּׁאָר הַסָּמוּךְ לוֹ וּמַעֲשֵׂר שֵׁנִי בְּפִי הַכּוֹס וַהֲרֵי הוּא מְחֻלָּל עַל הַמָּעוֹת וְשׁוֹתֶה וּמַנִּיחַ כְּדֵי תְּרוּמַת מַעֲשֵׂר בְּשׁוּלֵי הַכּוֹס:
כסף משנה
10.
If a common person gave him a cup [of wine] to drink [on the Sabbath], he should say:32This is an extension of the principles stated in Halachah 7. In this instance as well, the common person had invited him to dine with him on the Sabbath and thus he was unable to make the separations before the Sabbath. "What I will leave in the bottom of the cup is [part of] the tithes,33Since demai is a Rabbinic decree, we may rely on the principle of bereirah, that a separation made afterwards is retroactively considered as if was made beforehand. Thus the wine in the cup is not considered as tevel even though the tithes were not actually separated until later [the Rambam's Commentary to the Mishnah (Demai 72:2)]. as is the remainder of the tithes which are adjacent to it. That portion which I [first] designated as the tithes is terumat ma'aser for the remainder which is adjacent to it. The second tithe is located at the brim of the cup and its [holiness] is transferred to the money."34I.e., the money he has set aside at home for the redemption of the second tithe. He may then [drink] the cup, leaving a portion equivalent to [the amount to be separated as] terumat ma'aser351/100th of the cup. in the bottom of the cup.הלכה יא
וְכֵן אִם זִמְּנוֹ חֲבֵרוֹ לִשְׁתּוֹת בְּשַׁבָּת מַתְנֶה כִּתְנַאי זֶה מֵעֶרֶב שַׁבָּת עַל כָּל מַה שֶּׁיִּרְצֶה שֶׁיִּסְעֹד אֶצְלוֹ. וְכֵן פּוֹעֵל שֶׁאֵינוֹ מַאֲמִין לְבַעַל הַבַּיִת נוֹטֵל גְּרוֹגֶרֶת אַחַת וְאוֹמֵר זוֹ וְתֵשַׁע הַבָּאוֹת אַחֲרֶיהָ עֲשׂוּיוֹת מַעֲשֵׂר עַל הַמֵּאָה שֶׁאֲנִי עָתִיד לֶאֱכל וְזוֹ הָאַחַת תְּרוּמַת מַעֲשֵׂר עַל הָעֶשֶׂר הַבָּאוֹת אַחֲרֶיהָ וּמַעֲשֵׂר שֵׁנִי הוּא הָעֶשֶׂר הָאַחֲרוֹנוֹת וַהֲרֵי הוּא מְחֻלָּל עַל הַמָּעוֹת וְנוֹתֵן הַגְּרוֹגֶרֶת שֶׁהִפְרִישׁ לַכֹּהֵן. וְהַפּוֹעֵל מַפְרִישׁ לְעַצְמוֹ דְּמֵי מַעֲשֵׂר שֵׁנִי. שֶׁתְּנַאי בֵּית דִּין הוּא שֶׁתִּהְיֶה תְּרוּמַת מַעֲשֵׂר מִשֶּׁל בַּעַל הַבַּיִת וּמַעֲשֵׂר שֵׁנִי מִשֶּׁל פּוֹעֵל:
כסף משנה
11.
Similarly, if a colleague invites him to drink on the Sabbath,36The Radbaz questions why the Rambam deviates from the wording used by the Mishnah (Demai 7:1) which speaks of a person inviting a colleague to dine. he should make such a stipulation on Friday with regard to everything that he will desire to partake of at his [home].Similarly, when a worker does not trust his employer [with regard to the tithing of the food that he is given],37We are speaking about a situation in which the worker is entitled to partake of the produce as a result of a contractual stipulation and not because the Torah gives him the right to do so. See Chapter 5, Halachah 9. he should take one fig and say:38In contrast to the previous halachot, this is not speaking about a situation where the person partakes of the food on the Sabbath. Instead, it is speaking about a situation during the week and the separation is made at the time the tithes are designated. "This and the nine which follow are considered as tithes for the 100 that I will eat. This one is considered as terumat ma'aser for the ten39Actually, the nine. that follow. The ten40Here also, the intent is nine. See Chapter 7, Halachah 1. that follow after that are considered as the second tithe and their [holiness] is transferred to [this] money." He then takes the fig that he set aside and gives it to the priest.
The worker should separate the money for the second tithe from his own [funds].41Since he will use this money for food in Jerusalem, he will not suffer a loss by separating it from his own. For it is a condition of the court that the terumat ma'aser should come from the employer42I.e., the worker is entitled to take an extra fig from the employer as reimbursement for the produce he gives the priest as terumat ma'aser. and the second tithe from the worker.
הלכה יב
הַנַּחְתּוֹמִים לֹא חִיְּבוּם חֲכָמִים לְהַפְרִישׁ מַעֲשֵׂר שֵׁנִי מִן הַדְּמַאי אֶלָּא תְּרוּמַת מַעֲשֵׂר בִּלְבַד כְּדֵי שֶׁיַּפְרִישֶׁנָּה בְּטָהֳרָה עִם הַחַלָּה. וְהַלּוֹקֵחַ מַפְרִישׁ מַעֲשֵׂר שֵׁנִי. בַּמֶּה דְּבָרִים אֲמוּרִים בְּמוֹכֵר בַּחֲנוּתוֹ אוֹ עַל פֶּתַח חֲנוּתוֹ. אֲבָל הַמּוֹכֵר לְפַלְטֵר אוֹ בַּחֲנוּת הַסְּמוּכָה לְפַלְטֵר חַיָּב לְהַפְרִישׁ אַף מַעֲשֵׂר שֵׁנִי:
כסף משנה
12.
[Our Sages] did not obligate bakers to separate the second tithe [from grain] that is demai,43In his Commentary to the Mishnah (Demai 2:4, based on Yoma 9a), the Rambam writes that this leniency was instituted because the local officials would keep steady watch over the bakers and regulate their sales, preventing them from charging higher prices. In consideration of their position, our Sages did not require them to separate the second tithe. only terumat ma'aser. It is separated in a state of ritual purity together with the challah. The purchaser must separate the second tithe.44For he will not be suffering a loss, for he will use the money from the second tithe to purchase food in Jerusalem. For the baker, however, making this separation would be a severe loss, for he would never spend all the money for the grain he uses on his own provisions in Jerusalem.When does the above apply? To one who sells in his store or at the entrance to his store. If, however, he sells it to a wholesale baker or to a store adjacent to a wholesale baker,45In which instance, the initial baker is not pressured to lower his price to the same degree. he is obligated to separate the second tithe as well.
הלכה יג
שְׁנַיִם שֶׁבָּצְרוּ כַּרְמֵיהֶן בְּתוֹךְ גַּת אַחַת וְהָאֶחָד מֵהֶם אֵינוֹ נֶאֱמָן עַל הַמַּעַשְׂרוֹת. אַף עַל פִּי שֶׁעִשֵּׂר זֶה הַנֶּאֱמָן עַל חֶלְקוֹ כְּשֶׁהוּא נוֹטֵל חֶלְקוֹ מִן הַיַּיִן חַיָּב לְהַפְרִישׁ מִמֶּנּוּ מַעֲשֵׂר דְּמַאי עַל חֵלֶק עַם הָאָרֶץ. כֵּיצַד. הָיוּ מֶחֱצָה לְמֶחֱצָה וְנוֹטֵל בְּחֶצְיוֹ מָאתַיִם לוֹג יַיִן הֲרֵי זֶה מַפְרִישׁ מִמֶּנּוּ לוֹג אֶחָד תְּרוּמַת מַעֲשֵׂר וְעֶשֶׂר מַעֲשֵׂר שֵׁנִי כְּנֶגֶד הַמֵּאָה לוֹג שֶׁהֲרֵי הִפְרִישׁ הַמַּעֲשֵׂר שֶׁל וַדַּאי תְּחִלָּה עַל חֲצִי כָּל שֶׁדְּרָכוֹ בַּגַּת. וְכֵן אִם הָיָה שְׁלִישׁ אוֹ רְבִיעַ מַפְרִישׁ לְפִי חֶשְׁבּוֹן:
כסף משנה
13.
[The following rules apply when] two people harvested their vineyards into a common vat, and one of them is not trusted with regard to the tithes. Even though the one who is trusted [with regard to the tithes] already tithed his own produce,46I.e., they divided the grapes originally and he tithed his grapes before they were crushed and made into wine. when he takes his portion of the wine, he is obligated to separate tithes as one does for demai for the portion of the common person.47I.e., he must separate tithes for the share of his partner.What is implied? If they were equal partners and one takes 200 log as his portion, he should separate one log as terumat ma'aserand ten48Actually, the nine. log as the second tithe for the 100 log [of the common person]. [This is all that is required,] for he already separated the tithes for the produce that was definitely not tithed for half of the entire quantity in the vat.49We assume that each drop of wine is equally blended between the tithed portion and the portion that is demai. Thus the share to be tithed is no more than half the amount the person is taking, for he already separated the tithes for his own share.
In his gloss to this halachah, the Ra'avad questions the Rambam's ruling, noting that the restrictions regarding demai are Rabbinic in origin and that the principle of bereirah can be applied in questions of Rabbinic Law. Hence, based on this principle, we could say that retroactively, it could be considered that when the person separated the tithes for his portion, he was separating the tithes for the portion that he would ultimately receive.
The Ra'avad explains that it is possible to say that this principle is not applied as a penalty to the person. He is penalized, because he should not have mixed his produce with that of a common person. The Radbaz amplifies this explanation, stating that by mixing his produce together with that of a common person he caused the terumat ma'aser that will be separated to become impure. The Kessef Mishneh explains that initially when the separation was first made, the two batches of produce were not mixed together. Hence, it is not appropriate to say that the separation he is making now will affect the entire quantity.
If, however, they were full partners and did not make a division until the wine was produce, the person who is conscientious in his observance need not separate more than the tithes for his own portion. There is no need for him to be concerned about the share of the common person. For within this context, we apply the principle of bereirah and assume that retroactively, each one is receiving his own share and hence has no responsibility for the share of his colleague. Similarly, if his share was a third or a fourth, he must separate [the tithes from the produce he takes] proportionately.50If his share of the produce was one-third, he would have separated that amount of the total yield. Thus he would have to tithe two-thirds of the produce he receives.