זרעים
הלכות מעשר שני ונטע רבעי
פרק ג

Halacha

הלכה א
הָאוֹכֵל מַעֲשֵׂר שֵׁנִי בְּטֻמְאָה לוֹקֶה שֶׁנֶּאֱמַר (דברים כו יד) "וְלֹא בִעַרְתִּי מִמֶּנּוּ בְּטָמֵא". בֵּין שֶׁהַמַּעֲשֵׂר טָמֵא וְהָאוֹכֵל טָהוֹר. בֵּין שֶׁהַמַּעֲשֵׂר טָהוֹר וְהָאוֹכֵל טָמֵא. וְהוּא שֶׁיֹּאכְלֶנּוּ בִּירוּשָׁלַיִם קֹדֶם שֶׁיִּפָּדֶה. שֶׁאֵינוֹ לוֹקֶה עַל אֲכִילָתוֹ בְּטֻמְאָה אֶלָּא בִּמְקוֹם אֲכִילָתוֹ. אֲבָל אִם אֲכָלוֹ בְּטֻמְאָה חוּץ לִירוּשָׁלַיִם מַכִּין אוֹתוֹ מַכַּת מַרְדּוּת:
כסף משנה
1.
A person who partakes of produce from the second tithe in a state of ritual impurity is liable for lashes,1Sefer HaMitzvot (negative commandment 150) and Sefer HaChinuch (mitzvah 609) include this commandment among the 613 mitzvot of the Torah. as [implied by Deuteronomy 26:14]: "I did not consume it in a state of impurity." [This applies] whether the produce is impure and the person partaking of it is pure or the produce is pure and the person partaking of it is impure, provided he partakes of it in Jerusalem before it is redeemed.2For after the produce has been redeemed, it is ordinary produce. For one is liable for lashes for partaking of such produce in a state of ritual impurity in a place where it is fit to partake of it. If, however, one partakes of it in a state of ritual impurity outside of Jerusalem,3With regard to partaking of such produce outside of Jerusalem in a state of ritual purity, see the previous chapter. he is liable for stripes for rebellious conduct.4For the prohibition is only Rabbinic in origin. This applies even if the produce had already been brought into Jerusalem and was then removed.

הלכה ב
וַאֲפִלּוּ לְהַדְלִיק [בּוֹ] אֶת הַנֵּר אַחַר שֶׁנִּטְמָא אָסוּר עַד שֶׁיִּפָּדֶה שֶׁנֶּאֱמַר (דברים כו יד) "לֹא בִעַרְתִּי מִמֶּנּוּ בְּטָמֵא":
כסף משנה
2.
Once it has become impure,5I.e., even though it has become impure. Before it becomes impure, it is forbidden to use it for purposes other than human consumption, as stated in Halachah 10. it even forbidden to use such produce [as fuel] to kindle a lamp until it is redeemed, as [implied by]: "I did not consume it in a state of impurity."

הלכה ג
כְּבָר בֵּאַרְנוּ שֶׁהַמַּעֲשֵׂר שֶׁנִּטְמָא אֲפִלּוּ בִּירוּשָׁלַיִם פּוֹדִין וְיֵאָכֵל. וְאוֹכְלִין אֶת דָּמָיו בְּטָהֳרָה בְּתוֹרַת פֵּרוֹת מַעֲשֵׂר כְּמוֹ שֶׁיִּתְבָּאֵר. אֲפִלּוּ נִטְמְאוּ הַפֵּרוֹת כֻּלָּן כְּשֶׁהֵן טֶבֶל מַפְרִישׁ מַעֲשֵׂר שֵׁנִי בְּטֻמְאָה וּפוֹדֵהוּ:
כסף משנה
3.
We already explained,6Chapter 2, Halachah 8. that when produce from the second tithe becomes impure, it should be redeemed and eaten- even in Jerusalem.7Where it is otherwise forbidden to redeem produce from the second tithe. The proceeds [from its redemption] should [be used to purchase food that is] eaten in a state of ritual purity according to the laws governing produce from the second tithe, as will be explained.8See Halachot 10-11. Even if all the produce became impure while it was tevel, one should separate the second tithe in a state of ritual impurity9I.e., we do not say that since it became impure before the second tithe was separated and thus the mitzvah associated with that produce could never be fulfilled, the mitzvah does not take effect. and redeem it.

הלכה ד
הֶעָרֵל כְּטָמֵא וְאִם אָכַל מַעֲשֵׂר שֵׁנִי לוֹקֶה מִן הַתּוֹרָה כְּדֶרֶךְ שֶׁלּוֹקֶה עַל אֲכִילַת תְּרוּמָה. שֶׁהַתְּרוּמָה קְרוּיָה קֹדֶשׁ וּמַעֲשֵׂר שֵׁנִי קָרוּי קֹדֶשׁ שֶׁהֲרֵי נֶאֱמַר בּוֹ (ויקרא כז ל) "קֹדֶשׁ לַה'". וְטָמֵא שֶׁטָּבַל אוֹכֵל מַעֲשֵׂר שֵׁנִי אַף עַל פִּי שֶׁלֹּא הֶעֱרִיב שִׁמְשׁוֹ:
כסף משנה
4.
An uncircumcised person is considered as if he is ritually impure. If he partakes of produce from the second tithe, he is liable for lashes according to Scriptural Law as he is liable for lashes for partaking of terumah.10See Hilchot Terumah 7:10; see also Hilchot Ma'aseh HaKorbanot 10:9; Hilchot Chagigah 2:1. [This equivalence is established, because] terumah is referred to as "holy,"11Leviticus 22:10. and produce from the second tithe is referred as "holy," for [Leviticus 27:30] describes it as being "holy unto God."
When a person who was impure immerses himself [in a mikveh],12And thus performs the act necessary to emerge from ritual impurity. he may partake of produce from the second tithe even though the sun has not set that day.13A person who purified himself must wait until nightfall before partaking of terumah. This stringency does not apply with regard to partaking of produce from the second tithe.

הלכה ה
הָאוֹכֵל מַעֲשֵׂר שֵׁנִי בַּאֲנִינוּת שֶׁל תּוֹרָה לוֹקֶה שֶׁנֶּאֱמַר (דברים כו יד) "לֹא אָכַלְתִּי בְאֹנִי מִמֶּנּוּ". וְהוּא שֶׁיֹּאכְלֶנּוּ בְּמָקוֹם אֲכִילָתוֹ בִּירוּשָׁלַיִם. אֲבָל אִם אֲכָלוֹ בַּחוּץ בַּאֲנִינוּת. אוֹ שֶׁאֲכָלוֹ בִּפְנִים בַּאֲנִינוּת שֶׁל דִּבְרֵיהֶם. מַכִּין אוֹתוֹ מַכַּת מַרְדּוּת:
כסף משנה
5.
When a person partakes of produce from the second tithe in a Scripturally defined state of aninut,14See the following halachah. he is liable for lashes15Sefer HaMitzvot (negative commandment 151) and Sefer HaChinuch (mitzvah 608) include this commandment among the 613 mitzvot of the Torah.
The Rambam explains why he considers this a negative commandment in General Principle 8 of Sefer HaMitzvot, saying that whenever the Torah requires us to declare that we did not perform a specific activity, the performance of that activity is forbidden by Scriptural Law. The Ramban does not accept this principle as he states in his Hasagot.
as [implied by Deuteronomy 26:14]: "I did not consume it in a state of aninut." [This applies,] provided he partakes of it in the place we are commanded to partake of it, [i.e.,] in Jerusalem.16The Kessef Mishneh explains that this concept is derived from the prohibition against partaking of the second tithe in a state of ritual impurity which is mentioned in Halachah 1. Since the two prohibitions are mentioned in sequence by the Torah, we can assume that they share the same laws. If, however, he partook of such produce outside Jerusalem17Even if the produce had passed through Jerusalem previously. in a state of aninut or partook of it in Jerusalem in a Rabbinically defined state of aninut, he is given stripes for rebellious conduct.18For his actions involve either the violation of a positive Scriptural command or a Rabbinic ordinance.

הלכה ו
אֵיזֶהוּ אוֹנֵן זֶה הַמִּתְאַבֵּל עַל אֶחָד מִן הַקְּרוֹבִים שֶׁהוּא חַיָּב לְהִתְאַבֵּל עֲלֵיהֶן. וּבְיוֹם הַמִּיתָה הוּא אוֹנֵן מִן הַתּוֹרָה וּבַלַּיְלָה אוֹנֵן מִדִּבְרֵיהֶן שֶׁנֶּאֱמַר (ויקרא י יט) "וְאָכַלְתִּי חַטָּאת הַיּוֹם הַיִּיטַב בְּעֵינֵי ה'". הַיּוֹם אָסוּר וְלַיְלָה מֻתָּר. נִשְׁתַּהָה הַמֵּת יָמִים רַבִּים וְאַחַר כָּךְ נִקְבַּר. כָּל אוֹתָן הַיָּמִים שֶׁאַחַר יוֹם הַמִּיתָה עַד יוֹם הַקְּבוּרָה הוּא אוֹנֵן מִדִּבְרֵיהֶן. וְאֵין יוֹם הַקְּבוּרָה תּוֹפֵשׂ לֵילוֹ:
כסף משנה
6.
Who is an onain? One is mourning for one of the relatives for whom he is obligated to mourn19A person's mother, father, son, daughter, paternal brother and paternal sister (Hilchot Evel 2:1). on the day of their death is an onain according to Scriptural law. At night, he is an onain according to Rabbinic decree. [This is derived from Leviticus 10:19]: "If I would partake of a sin offering today, would it find favor in the eyes of God?"20Aaron asked this rhetorical question after Moses rebuked him for not partaking of the sin offering on the day of the dedication of the Sanctuary. Aaron was explaining that since his sons had died that day, it would not be appropriate for him to partake of a sin offering that day. [Implied is that the day is forbidden,21For the verse states today. but the night is permitted.22I.e., according to Scriptural Law; it is, however, forbidden by Rabbinic decree as above.
If the deceased remains [unburied] for several days and is not buried until afterwards, [his relatives are] onanim according to Rabbinic decree throughout the days from the day of death until the day of the burial. [The status of] the day of burial is not extended until [the following] night.23I.e., even according to Rabbinic Law, the laws of aninut do not apply.

הלכה ז
וְלֹא מַעֲשֵׂר שֵׁנִי בִּלְבַד אֶלָּא כָּל הַקָּדָשִׁים כֻּלָּן אִם אֲכָלָן בַּאֲנִינוּת שֶׁל תּוֹרָה לוֹקֶה. וּבַאֲנִינוּת שֶׁל דִּבְרֵיהֶן מַכִּין אוֹתוֹ מַכַּת מַרְדּוּת:
כסף משנה
7.
[This restriction does not apply] to the second tithe alone, [but also] to all sacrificial foods. If one partakes of them in a Scriptural state of aninut, he is liable for lashes. In a Rabbinic state of aninut, he is liable for stripes for rebellious conduct.24See Hilchot Bi'at HaMikdash 2:9-10. See Sefer HaMitzvot (negative commandment 151) which explains that the prohibition is included in this Scriptural commandment.

הלכה ח
אֵין נוֹתְנִין פֵּרוֹת מַעֲשֵׂר שֵׁנִי לְעַם הָאָרֶץ וְלֹא פֵּרוֹת הַנִּלְקָחוֹת בִּמְעוֹת מַעֲשֵׂר וְלֹא מְעוֹת מַעֲשֵׂר מִפְּנֵי שֶׁהוּא בְּחֶזְקַת טֻמְאָה. וּמֻתָּר לֶאֱכל מַעֲשֵׂר שֵׁנִי שֶׁל דְּמַאי בַּאֲנִינוּת וְלִתְּנוֹ לְעַם הָאָרֶץ וְהוּא שֶׁיֹּאכַל כְּנֶגְדּוֹ. אֵין מַפְקִידִין מַעֲשֵׂר שֵׁנִי אֲפִלּוּ אֵצֶל חָבֵר שֶׁמָּא יָמוּת וְנִמְצָא הַמַּעֲשֵׂר תַּחַת יַד בְּנוֹ עַם הָאָרֶץ. אֲבָל מַפְקִידִים מַעֲשֵׂר שֵׁנִי שֶׁל דְּמַאי אֵצֶל עַם הָאָרֶץ:
כסף משנה
8.
Produce from the second tithe, nor produce purchased with money from the second tithe, nor money from the redemption of the second tithe should not be given to a common person, because we operate under the assumption that he is impure.25And it is forbidden to cause produce from the second tithe to contract ritual impurity.
It is permitted to partake of produce from the second tithe that was separated from demai in a state of aninut26Even in a state of Scriptural aninut. and it may be given to a common person,27Although it may contract ritual impurity. The produce may not, however, be eaten in a state of ritual impurity until it is redeemed. The amount that may be given to a common person is, however, quite small, as stated in the following halachah. provided he eats [an equivalent amount of produce] in place of them.28I.e., he must separate an equivalent amount of produce from his possessions and partake of it according to the strictures of the second tithe. He is thus transferring the holiness of the first batch of produce to the second [the Rambam's Commentary to the Mishnah (Demai 1:2)]. Since the obligation to separate the second tithe from demai is Rabbinic in origin, certain leniencies are allowed.
Produce from the second tithe should not be entrusted [to a colleague for safekeeping], not even to a chavair,29The Ra'avad protests the Rambam's ruling. The Radbaz and the Kessef Mishneh explain that their disagreement stems from two different versions of the Tosefta (Ma'aser Sheni 4:3). lest he die and the produce will continue in the possession of his son, who is a common person. One may, however, entrust produce from the second tithe separated from demai to a common person.

הלכה ט
מַעֲשֵׂר שֵׁנִי אָסוּר לְאַבֵּד אֲפִלּוּ מִעוּטוֹ בַּדְּרָכִים. אֶלָּא מוֹלִיכוֹ כָּל שֶׁהוּא אוֹ מוֹלִיךְ דָּמָיו לִירוּשָׁלַיִם. וּמֻתָּר לְאַבֵּד מִעוּט מַעֲשֵׂר שֵׁנִי שֶׁל דְּמַאי בַּדְּרָכִים. וְכַמָּה הִיא מִעוּט פָּחוֹת מִכִּגְרוֹגֶרֶת בֵּין בְּאֹכֶל שָׁלֵם בֵּין בְּפָרוּס. אֲבָל כִּגְרוֹגֶרֶת אֵין מְאַבְּדִין אוֹתוֹ. וְהַמַּפְרִישׁ מַעֲשֵׂר שֵׁנִי שֶׁל דְּמַאי פָּחוֹת מִכִּגְרוֹגֶרֶת הֲרֵי זֶה נוֹתְנוֹ לְעַם הָאָרֶץ וְאוֹכֵל כְּנֶגְדּוֹ אֲבָל לֹא יַפְרִישֶׁנּוּ לְכַתְּחִלָּה לְאַבְּדוֹ שֶׁאֵין מַפְרִישִׁין לְאַבֵּד:
כסף משנה
9.
It is forbidden to cause the loss of even a small amount of produce from the second tithe30This is referring to an instance where we are certain that the second tithe was not separated from the produce beforehand in contrast to the second tithe that was separated from demai. on the journey [to Jerusalem].31In order to prevent this from happening, the Torah gave the option of redeeming the produce, as will be explained. Instead, one must transport it in its entirety or the proceeds [from its redemption] to Jerusalem. It is, however, permitted, to cause the loss of a small amount of produce from the second tithe separate from demai on the journey.
What is meant by a small portion? Less than the size of a dried fig,32See Hilchot Shabbat, chs. 8, 9, 18, which mention this measure as significant with regard to food (Kessef Mishneh). whether it is eaten whole or sliced. We may not, however, cause the loss of a portion the size of a dried fig.33The Ra'avad is more lenient and maintains that a larger amount, a portion the size of an egg, can be given to a common person. The Radbaz and the Kessef Mishneh explain that the difference in the two opinions depends in a textual difference in their versions of Jerusalem Talmud (Demai 2:1), the source for the Rambam's ruling.
When a person separates a portion less than the size of a dried fig from produce from the second tithe separated from demai, he may give it to a common person34Here also, the Ra'avad is more lenient and maintains that a larger amount, a portion the size of an egg, can be given to a common person. The Radbaz and the Kessef Mishneh explain that in this instance as well, the difference in the two opinions depends in a textual difference in their versions of the above source. provided he eats [a comparable portion in Jerusalem] in exchange for it. At the outset, he should not set it aside to be lost, for produce should not be set aside to be lost.

הלכה י
מַעֲשֵׂר שֵׁנִי נִתָּן לַאֲכִילָה וּשְׁתִיָּה שֶׁנֶּאֱמַר (דברים יד כג) "וְאָכַלְתָּ לִפְנֵי ה' אֱלֹהֶיךָ". וְסִיכָה כִּשְׁתִיָּה. וְאָסוּר לְהוֹצִיאוֹ בִּשְׁאָר צְרָכָיו כְּגוֹן לִקַּח בּוֹ כֵּלִים וּבְגָדִים וַעֲבָדִים שֶׁנֶּאֱמַר (דברים כו יד) "לֹא נָתַתִּי מִמֶּנּוּ לְמֵת" כְּלוֹמַר לֹא הוֹצֵאתִי אוֹתוֹ בְּדָבָר שֶׁאֵינוֹ מְקַיֵּם אֶת הַגּוּף. וְאִם הוֹצִיא מִמֶּנּוּ בִּשְׁאָר דְּבָרִים אֲפִלּוּ בִּדְבַר מִצְוָה כְּגוֹן שֶׁלָּקַח מִמֶּנּוּ אָרוֹן וְתַכְרִיכִין לְמֵת מִצְוָה הֲרֵי זֶה אוֹכֵל כְּנֶגְדּוֹ בְּתוֹרַת מַעֲשֵׂר:
כסף משנה
10.
The produce of the second tithe may be used to eat and to drink, as [implied by Deuteronomy 14:23]: "And you shall eat before God, your Lord."35And drinking is included in eating (Yoma 76b). In his Commentary to the Mishnah (Ma'aser Sheni 2:1), the Rambam also cites Deuteronomy 14:26 which speaks about using the money from the redemption of the produce from the second tithe to purchase meat, oil, and wine. Smearing oneself is considered as drinking.36In his Commentary to the Mishnah (ibid.), the Rambam cites the Jerusalem Talmud (Ma'aser Sheni 2:1) derives the permission to use oil from the second tithe for smearing as follows: It is forbidden to use oil for a corpse. Now why would oil be used for a corpse? To smear on it. Thus we can infer that it is permitted to use oil to smear on a living person. Others note that smearing oneself is frequently equated with drinking. See Hilchot Sh'vitat Esor 1:4-5; Hilchot Terumot 11:1.
It is forbidden to use [this produce] for any of one's other needs,37Sefer HaMitzvot (negative commandment 152; see also General Principle 8) and Sefer HaChinuch (mitzvah 610) include this commandment among the 613 mitzvot of the Torah. to purchase utensils, clothes, or servants, as [ibid. 26:14] states: "I did not give from it to a corpse," i.e., I did not use it [to purchase] an object that does not maintain the body.38In his Commentary to the Torah, the Ramban objects to the Rambam's interpretation of this verse, but the Kessef Mishneh justifies it. If a person uses this produce for other purposes, even for a mitzvah, e.g., he uses it to purchase a coffin and shrouds for an abandoned corpse,39The literal translation of the Rambam's words is "a corpse [that it is] a mitzvah [to bury]. As explained in Hilchot Evel 3:5, this refers to a corpse that is abandoned on the road without anyone to bury it. he must eat other food in place of it,40I.e., he is not liable for lashes, because he can correct the transgression by purchasing food worth the value of the produce and eating it in place of that produce (Radbaz). This applies if the seller is no longer present or he cannot return the money. If, however, he can return the money, he must, as stated in Chapter 7, Halachah 16. according to the laws governing the second tithe.

הלכה יא
מַעֲשֵׂר אוֹכֵל דָּבָר שֶׁדַּרְכּוֹ לְהֵאָכֵל וְשׁוֹתֶה דָּבָר שֶׁדַּרְכּוֹ לִשְׁתּוֹת וְסָךְ דָּבָר שֶׁדַּרְכּוֹ לָסוּךְ. וְלֹא יָסוּךְ יַיִן וְחֹמֶץ אֲבָל סָךְ הוּא אֶת הַשֶּׁמֶן. וְלֹא יִסְחֹט אֶת הַפֵּרוֹת לְהוֹצִיא מֵהֶן מַשְׁקִין חוּץ מִזֵּיתִים וַעֲנָבִים בִּלְבַד. [וְאֵין מְפַטְּמִין אֶת הַשֶּׁמֶן אֲבָל מְפַטְּמִין אֶת הַיַּיִן]. וְאֵין מְחַיְּבִין אוֹתוֹ לֶאֱכל פַּת שֶׁעִפְּשָׁה וְשֶׁמֶן שֶׁנִּסְרַח. אֶלָּא כֵּיוָן שֶׁנִּפְסַל מֵאֹכֶל אָדָם פָּקְעָה קְדֻשָּׁה מִמֶּנּוּ:
כסף משנה
11.
[With regard to produce from the second] tithe: One should eat produce that is normally eaten,41In his Commentary to the Mishnah (Ma'aser Sheni 2:1), the Rambam explains that this phrase implies an exclusion: Something that is normally eaten must be eaten. We cannot benefit from it in another manner. The examples the Rambam proceeds to give reflect how foods are used for functions other than their primary purpose. See also Hilchot Shemitah 5:2-3. drink what is normally drunk, and smear on oneself what is normally smeared. He should not smear wine or vinegar, but he may smear oil.42Even though oil is primarily used as food, it is also common to smear it on one's flesh (Radbaz). Wine or vinegar, by contrast, are generally not applied as ointments. He should not squeeze fruit to extract its juice with the exception of olives and grapes.43For producing juice from other fruits is not considered the ordinary way of benefitting from this produce. See also Chapter 9, Halachah 3; Hilchot Terumot 11:3; Hilchot Tuma'at Ochalin 1:5. We do not mix spices with oil, 44For this spoils the oil's taste and thus reduces the amount of people who would partake of it [The Rambam's Commentary to the Mishnah (loc. cit.)]. but do so with wine.45For this enhances the wine's taste.
We do not require a person to eat bread that has become moldy or oil that has become rancid. Instead, as soon as it has become spoiled to the point that it is not fit for human consumption, its holiness has departed from it.46In his Commentary to the Mishnah (loc. cit., the Rambam explains that this concept is also derived from the phrasing of that Mishnah: "To eat what is normally eaten." Since this food has spoiled, it is not "normally eaten."

הלכה יב
כָּל שֶׁמֻּתָּר לְזָרִים לְאָכְלוֹ בִּתְרוּמָה כָּךְ מֻתָּר בְּמַעֲשֵׂר שֵׁנִי לְאָכְלוֹ בְּתוֹרַת חֻלִּין. שְׁמָרִים שֶׁל מַעֲשֵׂר שֵׁנִי שֶׁנָּתַן עֲלֵיהֶם מַיִם. רִאשׁוֹן אָסוּר כְּמַעֲשֵׂר וְשֵׁנִי מֻתָּר כְּחֻלִּין. וְשֶׁל דְּמַאי אֲפִלּוּ רִאשׁוֹן מֻתָּר:
כסף משנה
12.
Whatever parts of produce from terumah that non-priests are permitted to eat47I.e., parts of the plant that are not usually eaten. See Hilchot Terumah 11:10-13 for examples. may also be eaten from produce of the second tithe like ordinary produce.48I.e., it need not be eaten in Jerusalem, nor in a state of ritual purity. When [grape] dregs from the second tithe were placed in water,49To impart their flavor to the water. the first [quantity of drink produce] is forbidden like the produce from the second tithe.50For it is considered as if a significant amount of the fruit was imparted to the water. The second is permitted, like ordinary produce.51Because it does not contain a significant amount of the fruit. [If the produce of the second tithe was] from demai, even the first quantity is permitted.52Since there is a doubt whether the produce is really from the second tithe, we do not impose this stringency.

הלכה יג
יַיִן שֶׁל מַעֲשֵׂר שֶׁנָּפַל לְתוֹכוֹ דְּבַשׁ וְהַתַּבְלִין וְהִשְׁבִּיחוּ הַשֶּׁבַח לְפִי חֶשְׁבּוֹן. וְכֵן דָּגִים שֶׁנִּתְבַּשְּׁלוּ עִם קַפְלוֹטוֹת שֶׁל מַעֲשֵׂר שֵׁנִי וְהִשְׁבִּיחוּ הַשֶּׁבַח לְפִי חֶשְׁבּוֹן:
כסף משנה
13.
When honey and spices53That were ordinary produce. fell into wine from the second tithe and improved its flavor, the improvement is judged proportionately.54As explained in Halachah 15. Similarly, if fish were cooked with leek from the second tithe and their flavor was improved, the improvement is judged proportionately.

הלכה יד
עִסָּה שֶׁל מַעֲשֵׂר שֵׁנִי שֶׁאֲפָאָהּ וְהִשְׁבִּיחָה הַשֶּׁבַח לַשֵּׁנִי. זֶה הַכְּלָל כָּל שֶׁשִּׁבְחוֹ נִכָּר אִם הוֹתִיר בְּמִדָּה הַשֶּׁבַח לְפִי חֶשְׁבּוֹן. וְאִם לֹא הוֹתִיר הַמִּדָּה הַשֶּׁבַח לַשֵּׁנִי בִּלְבַד. וְכָל שֶׁאֵין שִׁבְחוֹ נִכָּר אֲפִלּוּ הוֹתִיר הַמִּדָּה הַשֶּׁבַח לַשֵּׁנִי בִּלְבַד:
כסף משנה
14.
When a dough made with flour from the second tithe was baked55With ordinary wood [the Rambam's Commentary to the Mishnah (Ma'aser Sheni 2:1)]. and improved, the improvement is accredited to the second tithe.56I.e., if one seeks to redeem the bread, one must pay its full value, even though as dough it was worth far less. The rationale is that its flavor is enhanced, but not its measure. This is the general principle: Whenever the improvement57In the taste of the produce.
The Ra'avad has protested this ruling based on the Jerusalem Talmud (Ma'aser Sheni 2:1). Indeed, the ruling is difficult to understand because it runs contrary to the Rambam's commentary on the Mishnah that serves as the source for the Jerusalem Talmud.
To explain: The Mishnah states: "This is the general principle: Whenever the improvement is obvious, the improvement is judged proportionately. Whenever the improvement is not obvious, the improvement is accredited to the second [tithe]."
The Rambam comments: "I.e., the entity that was improved had its weight... and volume increased, it is not [merely] that the effect of the ordinary produce increased the quality of the produce from the second tithe."
The Jerusalem Talmud cites the following difference of opinion between Rabbi Yochanan and Reish Lakish in connection with our Mishnah:

Rabbi Yochanan says: "Whenever the volume of the produce has increased, the increase is proportionate. Whenever the volume has not increased, the increase is accredited to the second tithe."
Reish Lakish says: "Whenever the improvement in flavor is obvious, the increase is proportionate. Whenever the improvement in flavor is not obvious, the increase is accredited to the second tithe."

Now the general rule is that whenever there is a difference of opinion between Rabbi Yochanan and Reish Lakish, the halachah follows Rabbi Yochanan. The Radbaz and the Kessef Mishneh understand Rabbi Yochanan to be explaining and amplifying the Mishnah, stating that the improvement must be both in flavor and in size, while Reish Lakish maintains that an improvement in flavor is also sufficient.
is obvious, if the volume of the produce is increased, the improvement is judged proportionately. If the volume of the produce is not increased, the improvement is accredited to the second tithe alone. Whenever the improvement is not obvious, the improvement is attributed to the second tithe alone even when the volume is not increased.

הלכה טו
כֵּיצַד הַשֶּׁבַח. לְפִי חֶשְׁבּוֹן. יַיִן שֶׁל מַעֲשֵׂר שֶׁשָּׁוֶה שְׁלֹשָׁה שֶׁנָּפַל לְתוֹכוֹ דְּבַשׁ וְתַבְלִין שָׁוֶה זוּז אֶחָד וְהוֹסִיפָה בְּמִדָּתוֹ וְהִשְׁבִּיחוּהוּ וַהֲרֵי הַכּל שָׁוֶה חֲמִשָּׁה חוֹשְבִין הַכּל בְּאַרְבָּעָה וּרְבִיעַ. וְכֵן עַל דֶּרֶךְ זֶה בִּשְׁאָר הַדְּבָרִים:
כסף משנה
15.
What is meant by the phrase "the improvement is judged proportionately"? Honey and spices worth a zuz fall into wine from the second tithe that is worth three [zuz], increasing its volume and improving its flavor.58Thus meeting the two requirements mentioned above. The combined worth is now five zuz, we consider the worth [for the tithes] as four and a fourth.59The Ra'avad objects to the Rambam's ruling and states that four zuz minus a fourth should be considered as the second tithe. Some commentaries suggest that there is a printing error and the Rambam also agrees with this ruling. "According to that version, the reckoning is straightforward. The zuz of increase is divided proportionately according to the ratio of the original value of the substances.
The Kessef Mishneh maintains the present text of the Mishneh Torah and explains as follows: When everything belongs to one person, three and three quarters zuz are considered as the second tithe as the Ra'avad maintains. When, however, the honey and spices belong to two people, the value of the entire mixture is considered as four and a fourth zuz. One and a fourth is given to the owner of the honey. Thus the owner of the wine has three and three fourths zuz worth which he must eat in accordance with the laws of the second tithe. Note the Rambam's Commentary to the Mishnah (Ma'aser Sheni 2:1) which follows these same principles, but describes the situation differently.
Similar rules apply with regard to other substances.

הלכה טז
מַעֲשֵׂר שֵׁנִי אַף עַל פִּי שֶׁנִּתָּן לְסִיכָה אֵין נוֹתְנִין אוֹתוֹ לֹא עַל גַּבֵּי צִינִית וְלֹא עַל גַּבֵּי חֲזָזִית. וְאֵין עוֹשִׂין מִמֶּנּוּ קָמֵעַ וְכַיּוֹצֵא בּוֹ שֶׁהֲרֵי לֹא נִתַּן לִרְפוּאָה:
כסף משנה
16.
Although produce from the second tithe may be used for smearing,60As stated in Halachah 10. it should not be placed on a foot infection or on boils, nor may it be used as an amulet or the like, because it was not intended to be used as medication.61But rather as food, or for smearing that is pleasurable like eating (Radbaz). Note the parallel in Hilchot Shemitah 5:11.

הלכה יז
מַעֲשֵׂר שֵׁנִי מָמוֹן גָּבוֹהַּ הוּא שֶׁנֶּאֱמַר (ויקרא כז ל) "לַה' הוּא". לְפִיכָךְ אֵינוֹ נִקְנֶה בְּמַתָּנָה אֶלָּא אִם כֵּן נָתַן לוֹ הַטֶּבֶל וְהַמְקַבֵּל מַפְרִישׁ הַמַּעֲשֵׂר. וְאֵין מְקַדְּשִׁין בּוֹ אֶת הָאִשָּׁה וְאֵין מוֹכְרִין אוֹתוֹ וְאֵין מְמַשְׁכְּנִין אוֹתוֹ וְאֵין מַחְלִיפִין אוֹתוֹ וְאֵין מַרְהִינִין אוֹתוֹ:
כסף משנה
17.
The second tithe is considered the property of the Most High, as [Leviticus 27:30] states: "It is God's." Therefore it cannot be acquired [when given] as a present,62The Rambam is not saying that it may not be given as a present, because a person may give produce from the second tithe tithe to a colleague. Nevertheless, the recipient does not acquire that produce as his own. Instead, it is as if he is a guest of the giver, partaking of his property. More particularly, it is as if the recipient is partaking of God's property. unless one gives a colleague tevel and he separates the second tithe from it.
It may not be used to consecrate a woman,63Indeed, if one attempts to consecrate a woman with such produce, the consecration is not effective, for the money used to consecrate a woman must belong to the husband (Hilchot Ishut 5:4,6). nor may it be sold, nor may it be taken as security.64See the following halachah for examples of all these prohibitions. It may not be exchanged,65For an exchange is equivalent to a sale [the Rambam's Commentary to the Mishnah (Ma'aser Sheni 1:1)]. nor may it be given as surety.

הלכה יח
כֵּיצַד אֵין מְמַשְׁכְּנִין אוֹתוֹ. לֹא יִכָּנֵס לְבֵיתוֹ וִימַשְׁכְּנֶנּוּ מַעֲשֵׂר שֵׁנִי שֶׁלּוֹ. עָבַר וּמִשְׁכְּנוֹ מוֹצִיאִין אוֹתוֹ מִיָּדוֹ. כֵּיצַד אֵין מַרְהִינִין אוֹתוֹ. לֹא יֹאמַר לוֹ הֵא לְךָ מַעֲשֵׂר זֶה וְיִהְיֶה בְּיָדְךָ וְתֵן לִי עָלָיו מָעוֹת. כֵּיצַד אֵין מַחְלִיפִין אוֹתוֹ. לֹא יֹאמַר לוֹ הֵא לְךָ יֵין מַעֲשֵׂר וְתֵן לִי שֶׁמֶן מַעֲשֵׂר. אֲבָל אוֹמֵר לוֹ הֵא לְךָ יַיִן שֶׁאֵין לִי שֶׁמֶן וְאִם רָצָה חֲבֵרוֹ לִתֵּן לוֹ שֶׁמֶן מֻתָּר שֶׁהֲרֵי לֹא הֶחֱלִיף עִמּוֹ אֶלָּא הוֹדִיעוֹ שֶׁאֵין לוֹ וְאִם רָצָה הַלָּה לִתֵּן יִתֵּן:
כסף משנה
18.
What is meant by the prohibition against taking it as security? One should not enter [the debtor's] home66See Hilchot Malveh veLoveh 3:7 which describes when a creditor can enter the debtor's home to collect security. and take produce from the second tithe of his as security. If one transgressed and took such produce as security, it is expropriated from him.
What is meant by the prohibition against giving it as surety? One should not tell a colleague: "Take this produce from the second tithe. Keep it in your possession and lend me money because of it."67In contrast to the previous instance, this is referring to security willingly given by the debtor to the creditor.
What is meant by the prohibition against exchanging it? A person should not tell a colleague: "Here is wine from the second tithe for you and give me oil from the second tithe."68I.e., the exchange is forbidden even if he receives produce from the second tithe in return. The Mishnah (Ma'aser Sheni 1:1)] states that such an exchange is forbidden even in Jerusalem where the produce would be eaten. He may, however, tell a colleague: "Here is wine from [the second tithe] for you, but I don't have oil." If his colleague desires to give him oil, it is permitted, because he did not exchange it with him.69For the recipient of the wine is under no obligation to provide the giver with oil or anything else. He merely notified him that he lacked it. Thus, if that person desired to give him, he may.

הלכה יט
מַעֲשֵׂר שֵׁנִי אֵין שׁוֹקְלִין כְּנֶגְדּוֹ אֲפִלּוּ דִּינְרֵי זָהָב. וַאֲפִלּוּ לְחַלֵּל עֲלֵיהֶם מַעֲשֵׂר שֵׁנִי אַחֵר גְּזֵרָה שֶׁמָּא לֹא יְכַוֵּן מִמֶּנּוּ מִשְׁקָלוֹ וְנִמְצְאוּ הַפֵּרוֹת חֲסֵרִים וְהוּא שׁוֹקֵל בָּהֶן מָעוֹת לְחַלֵּל עֲלֵיהֶם מַעֲשֵׂר אַחֵר נִמְצָא מוֹצִיא מַעֲשֵׂר לְחֻלִּין בְּפָחוֹת בְּדָמָיו:
כסף משנה
19.
We do not use produce from the second tithe as a weight for anything, even for golden dinarim.70For this is deprecating to the holiness of the second tithe [the Rambam's Commentary to the Mishnah (Ma'aser Sheni 1:1)]. [This is forbidden] even to [weigh coins] onto which the holiness from other produce will be transferred.71I.e., one knows the weight of the produce and one uses it in order to weigh the golden coins onto which the holiness from other produce from the second tithe will be transferred. [This is] a decree,72I.e., one might think that this is permitted for after all, he is using the produce from the second tithe for a mitzvah, to enable him to transfer the holiness of other produce. [enacted] lest he balance his scales on this basis and the produce be lacking in weight.73I.e., the produce may dry out, be eaten by mice, or spoil, and thus weigh less than the owner thought (Rav Yosef Corcus). Thus if he uses them to weigh coins upon which to transfer the holiness of other produce from the second tithe, he will be redeeming such produce for less than its worth.

הלכה כ
הָאַחִים שֶׁחָלְקוּ מַעֲשֵׂר שֵׁנִי אֵין שׁוֹקְלִין זֶה כְּנֶגֶד זֶה וְכֵן מְעוֹת מַעֲשֵׂר שֵׁנִי אֵין שׁוֹקְלִים כְּנֶגְדָּן וְאֵין מוֹכְרִין אוֹתָם וְאֵין מַחְלִיפִין וְלֹא מַרְהִינִין. וְלֹא יִתְּנֵם לְשֻׁלְחָנִי לְהִתְנָאוֹת בָּהֶן וְלֹא יַלְוֶה אוֹתָן לְהִתְגַּדֵּל בָּהֶן. וְאִם הִלְוָן שֶׁלֹּא יַעֲלֶה חֲלֻדָּה מֻתָּר:
כסף משנה
20.
When brothers divide produce from the second tithe [left them in an estate], they should not weigh them against each other.74The Ra'avad differs with the Rambam and maintains that this is permitted. The Kessef Mishneh states that the passage which the Ra'avad uses as a source can be explained differently. Nevertheless, he questions the rationale for the Rambam's ruling. Similarly, coins [upon which the holiness of] the second tithe [has been transferred] should not be weighed against each other. [Such coins] should not be sold, nor exchanged, nor given as surety. One may not give them to a moneychanger to use to create an impression.75I.e., to stack them on his table so that he will appear to have an active business. One may not lend them to boost his image.76One gives the loan only for appearance sake - to create an impression that he is wealthy - and the borrower returns it immediately. It is, however, permitted to lend them so that they will not rust.

הלכה כא
וְאֵין פּוֹרְעִין מֵהֶם אֶת הַמִּלְוֶה. אֵין עוֹשִׂין מֵהֶן שׁוֹשְׁבִינוּת וְאֵין מְשַׁלְּמִין מֵהֶן הַגְּמוּלִין. וְאֵין פּוֹסְקִין מֵהֶם צְדָקָה בְּבֵית הַכְּנֶסֶת. אֲבָל מְשַׁלְּמִין מֵהֶן דְּבָרִים שֶׁהֵן גְּמִילוּת חֲסָדִים. וְצָרִיךְ לְהוֹדִיעַ:
כסף משנה
21.
We may not use [this money] to repay loans. They may not be used as wedding gifts,77It was customary for a person's friends to give him money as a wedding gift and for him to repay the favor when the friends married. See Hilchot Zechiyah UMatanah, ch. 7, for a detailed explanation. This is forbidden, because the present is considered as a loan. nor may they be used to repay favors.78I.e., a person invited a colleague for a meal with the expectation that the colleague return the favor (P'nei Moshe, the Jerusalem Talmud, Demai 3:1). Produce from the second tithe cannot be used for such meals, for it is like an exchange. They may not be used to pay for charity levied upon him in the synagogue.79For he will be paying an obligation levied upon him with funds belonging to God (ibid.). One may, however, send them [as gifts] for charitable purposes.80As long is the donor is not obligated to make these payments. One must, however, [notify the recipient].81So that he will use it as required for money from the second tithes.

הלכה כב
לֹא יֹאמַר אָדָם לַחֲבֵרוֹ הַעַל אֶת הַפֵּרוֹת הָאֵלּוּ לִירוּשָׁלַיִם וְטל מֵהֶן חֶלְקְךָ שֶׁנִּמְצָא זֶה כְּנוֹטֵל שָׂכָר מִמַּעֲשֵׂר שֵׁנִי עַל הֲבָאָתוֹ לִירוּשָׁלַיִם. אֲבָל אוֹמֵר לוֹ הַעְלֵם שֶׁנֹּאכְלֵם וְשֶׁנִּשְׁתֵּם בִּירוּשָׁלַיִם:
כסף משנה
22.
A person should not tell a colleague: "Bring this produce to Jerusalem and take your wages from it," for such an arrangement is equivalent to taking his wages for transporting the produce to Jerusalem.82That would be forbidden because it would be equivalent to using the produce from the second tithe to pay his debt. He may, however, tell him: "Bring it to Jerusalem so that we can eat it and drink it there."83Hinting at such an arrangement without specifically mentioning it.

הלכה כג
אוֹמֵר אָדָם לַחֲבֵרוֹ בִּירוּשָׁלַיִם לָסוּךְ אוֹתוֹ בְּשֶׁמֶן מַעֲשֵׂר שֵׁנִי אַף עַל פִּי שֶׁנִּסּוֹכָה יָדוֹ וְאֵין זֶה בִּשְׂכַר סִיכָתוֹ:
כסף משנה
23.
In Jerusalem, a person may ask a colleague to smear oil from the second tithe upon him even though the oil also becomes smeared on the colleague's hand. This is not considered as a wage for smearing it upon him.84This is permitted, because the oil smeared on his hand is not financially significant [the Rambam's Commentary to the Mishnah (Ma'aser Sheni 2:2)]. Nevertheless, a non-priest is not to put oil which is terumah on his hand to smear it on a priest. The difference between the two situations is that there is no prohibition against having a colleague use oil from the second tithe, while a non-priest is not allowed to benefit from terumah.

הלכה כד
כְּבָר בֵּאַרְנוּ שֶׁהַמַּעֲשֵׂר מָמוֹן גָּבוֹהַּ הוּא. לְפִיכָךְ אָנוּ אוֹמְרִים שֶׁהַגּוֹנֵב מַעֲשֵׂר שֵׁנִי אֵינוֹ מְשַׁלֵּם תַּשְׁלוּמֵי כֶּפֶל וְהַגּוֹזְלוֹ אֵינוֹ מְשַׁלֵּם חֹמֶשׁ:
כסף משנה
24.
We have already explained85Halachah 17. that the produce from the second tithe belongs to the Most High. Therefore we say that one who steals produce from the second tithe is not obligated to make a double payment, nor is one who robs it obligated to add a fifth.86These are the penalties one would be required to pay for taking a person's individual property. The thief is, however, required to return the principal. See Hilchot Geneivah 2:1.

הלכה כה
הַמַּקְדִּישׁ מַעֲשֵׂר שֵׁנִי שֶׁלּוֹ לְבֶדֶק הַבַּיִת הֲרֵי זֶה פּוֹדֶה אוֹתוֹ מִי שֶׁפּוֹדֵהוּ עַל מְנָת לִתֵּן לַהֶקְדֵּשׁ אֶת שֶׁלּוֹ וּלְמַעֲשֵׂר שֵׁנִי אֶת שֶׁלּוֹ:
כסף משנה
25.
When a person consecrates produce from the second tithe to the Temple treasury,87The consecration is effective. Since the person has the right to partake of the produce, that right has monetary value and hence may be consecrated. See Chapter 7, Halachah 19, with regard to dedicating the second tithes for the purchase of sacrifices. the one88I.e., not necessarily the owner, for anyone can redeem consecrated property. The owner, however, must add a fifth (see Hilchot Arachin 7:2-4). Similarly, when a person redeems produce from the second tithe that belongs to him, he must add a fifth, as stated in Chapter 5, Halachah 1. See Radbaz. who redeems it should redeem it with the intent of giving what is due to the Temple treasury to it and what is due to the second tithe to it.

זרעים הלכות מעשר שני ונטע רבעי פרק ג
Zeraim Maaser Sheini and Neta Revai Chapter 3