זרעים
הלכות מתנות עניים
פרק ג

Halacha

הלכה א
אֵין מַנִּיחִין אֶת הַפֵּאָה מִשָּׂדֶה עַל חֲבֶרְתָּהּ. כֵּיצַד. הָיוּ לוֹ שְׁתֵּי שָׂדוֹת לֹא יִקְצֹר אֶת הָאַחַת כֻּלָּהּ וְיַנִּיחַ בַּשְּׁנִיָּה פֵּאָה הָרְאוּיָה לִשְׁתֵּיהֶן. שֶׁנֶּאֱמַר (ויקרא כג כב) "לֹא תְכַלֶּה פְּאַת שָׂדְךָ בְּקֻצְרֶךָ" שֶׁיַּנִּיחַ בְּכָל אַחַת וְאַחַת פֵּאָה הָרְאוּיָה לָהּ. וְאִם הִנִּיחַ מִשָּׂדֶה עַל חֲבֶרְתָּהּ אֵינָהּ פֵּאָה:
כסף משנה
1.
Pe'ah should not be left in one field for another field.
What is implied? If [a person] owned two fields, he should not harvest one entirely and leave the amount of pe'ah appropriate for both in the second field. [This is derived from Leviticus 23:22:] "Do not completely remove [the grain in] the corners of your field." [Implied is] that one should leave in each field the pe'ah that is appropriate for it. If one left [pe'ah] from one field for another, it is not pe'ah.

הלכה ב
הָיְתָה שָׂדֵהוּ זְרוּעָה כֻּלָּהּ מִין אֶחָד וְהָיָה נַחַל בְּתוֹךְ הַשָּׂדֶה אַף עַל פִּי שֶׁאֵינוֹ מוֹשֵׁךְ. אוֹ אַמַּת הַמַּיִם שֶׁאֵינוֹ יָכוֹל לִקְצֹר מַה שֶּׁבִּשְׁנֵי צְדָדֶיהָ כְּאַחַת וְהוּא שֶׁתִּהְיֶה מוֹשֶׁכֶת וּקְבוּעָה. הֲרֵי זֶה כִּשְׁתֵּי שָׂדוֹת וְנוֹתֵן פֵּאָה מִצַּד זֶה לְעַצְמוֹ וּמִצַּד זֶה לְעַצְמוֹ:
כסף משנה
2.
Although one's entire field was sowed with one crop, if there was a stream - even if did not flow1I.e., even if at the time the stream was dried out, the ravine itself constitutes a separation (Radbaz). The Kessef Mishneh, however, interprets the Rambam as referring to a stream with water. - or an irrigation ditch - provided water flowed through it and it was established2I.e., an irrigation ditch constitutes a separation only when water flows through it throughout the year. - in the midst of the field that would prevent one from harvesting both sides at the same time,3In his Commentary on the Mishnah (Pe'ah 2:2), the Rambam explains that this refers to a situation where a person standing on one side of the irrigation ditch cannot extend his hand and harvest the produce growing on the other. it is considered as two fields and one should give pe'ah on each side for the portion there.

הלכה ג
וְכֵן אִם הָיָה מַפְסִיק דֶּרֶךְ הַיָּחִיד שֶׁהוּא רָחָב אַרְבַּע אַמּוֹת אוֹ דֶּרֶךְ הָרַבִּים הָרָחָב שֵׁשׁ עֶשְׂרֵה אַמָּה. אֲבָל שְׁבִיל הַיָּחִיד וְהוּא פָּחוֹת מֵאַרְבַּע אוֹ שְׁבִיל הָרַבִּים פָּחוֹת מִשֵּׁשׁ עֶשְׂרֵה אַמָּה אִם הָיָה קָבוּעַ בִּימוֹת הַחַמָּה וּבִימוֹת הַגְּשָׁמִים מַפְסִיק. וְאִם אֵינוֹ קָבוּעַ בִּימוֹת הַגְּשָׁמִים אֵינוֹ מַפְסִיק אֶלָּא הֲרֵי הוּא כְּשָׂדֶה אַחַת:
כסף משנה
3.
Similarly, a path belonging to a private individual which is four cubits wide or a public thoroughfare which is sixteen cubits wide separates [between one field and another]. [Different rules apply regarding] a private path that is less than four cubits wide or a public path that is less than sixteen cubits wide.4In his Commentary on the Mishnah (ibid.), the Rambam makes a distinction between a path owned by a private individual and one used by people at large, explaining that a path owned by a private person is continually used by him. Hence, even if it is narrow, it is considered a separation. The public, by contrast, has many paths at their disposal and will not necessarily follow a particular path. Hence, unless a public path is very wide or permanent, it is not considered as a separation. If it is permanent, i.e., it is maintained in the summer and in the rainy season, it is considered as a separation. If it is not permanent in the rainy season, it is not considered as a separation and [the entire area] is considered as one field.

הלכה ד
הָיָה מַפְסִיק בָּהּ אֶרֶץ בּוּרָה שֶׁאֵינָה זְרוּעָה וְלֹא חֲרוּשָׁה. אוֹ אֶרֶץ נִירָה וְהִיא שֶׁנֶּחֶרְשָׁה וְלֹא נִזְרְעָה. אוֹ שֶׁהִפְסִיק בָּהּ זֶרַע אַחֵר. כְּגוֹן שֶׁהָיָה חִטִּים מִכָּאן וְחִטִּים מִכָּאן וּשְׂעוֹרִים בָּאֶמְצַע. אוֹ שֶׁקָּצַר בְּאֶמְצָעָהּ אֲפִלּוּ קֹדֶם שֶׁתָּבִיא שְׁלִישׁ וְחָרַשׁ מָקוֹם שֶׁקָּצַר. הֲרֵי זוֹ נִפְסֶקֶת לִשְׁתֵּי שָׂדוֹת. וְהוּא שֶׁיִּהְיֶה רֹחַב כָּל אֶחָד מֵאֵלּוּ כִּשְׁלֹשָׁה תְּלָמִים שֶׁל פָּתִיח וְהוּא פָּחוֹת מִבֵּית רֹבַע. בַּמֶּה דְּבָרִים אֲמוּרִים בְּשָׂדֶה קְטַנָּה שֶׁהִיא חֲמִשִּׁים אַמָּה שֶׁל שְׁתֵּי אַמּוֹת אוֹ פָּחוֹת. אֲבָל אִם הָיְתָה יְתֵרָה עַל זוֹ אֵין הַבּוּר אוֹ הַנִּיר מַפְסִיקָהּ לִשְׁתַּיִם אֶלָּא אִם כֵּן הָיְתָה בּוֹ רֹחַב בֵּית רֹבַע. אֲבָל זֶרַע אַחֵר כָּל שֶׁהוּא מַפְסִיק בָּהּ:
כסף משנה
4.
There are other factors which constitute a separation into two fields:
a) land that was uncultivated, that was neither sown, nor plowed;
b) land left fallow, that was plowed, but not sown;
c) crops were interrupted with another crop, e.g., there was wheat on either side and barley in the middle;5We are speaking here about a situation where it is unnecessary to make a separation because of the laws of kilayim (mixed species; see Hilchot Kilayim, the latter part of ch. 3). If it is necessary to make a separation for that reason, that separation will be large enough to constitute a separation for pe'ah as well.
d) one harvested in the middle of his field before the grain reached a third of its maturity and plowed the portion which he harvested.6As stated in Chapter 2, Halachah 7, one is not obligated to leave pe'ah for such a field if he harvested it in such a preliminary state. Nevertheless, unless he plows it, the harvest alone is not considered significant enough to have divided the field with regard to the other crops (Kessef Mishneh). Needless to say, if it already grew to a third of its development and hence required pe'ah for its own crop, it is only considered as a divider if the land was plowed (Radbaz).
[The above applies] provided the width of each of the above is three rows of plowing. [This is] less7According to the Rambam's opinion, this is a far smaller figure, while according to the Ra'avad, the difference is not that great (Radbaz). The Ra'avad bases his interpretation on the treatment of this subject in the Jerusalem Talmud (Pe'ah 2:2), claiming that that text does not support the Rambam's ruling. The Kessef Mishneh explains that there is a version of the Jerusalem Talmud that supports the Rambam's position and maintains that the Ra'avad's version is in error. than the area necessary to sow a quarter [of a kav].8The latter measure is slightly more than ten and one fifth cubits by ten and one fifth cubits (Hilchot Kilayim 3:9 and notes).
When does the above apply? With regard to a small field that is 50 cubits by two cubits or less. If it is larger than this uncultivated or fallow land does not cause it to be divided in two unless it was as wide as the area necessary to sow a quarter of a kav.9Since the entire field is larger, the area which creates the separation must also be larger. [In this instance,] even the smallest amount of another crop creates a separation.10The Radbaz questions why leniency is granted with regard to separation when another crop is sown and explains that it is uncommon to sow a small amount of a second crop in between two larger portions of one crop. Hence, one can assume that it was done so only for the sake of making a distinction.

הלכה ה
אֲכָלָהּ גּוֹבַאי אוֹ קִרְסְמוּהָ נְמָלִים בְּאֶמְצָעָהּ אִם חָרַשׁ מָקוֹם שֶׁאָכְלוּ הֲרֵי זֶה מַפְסִיק:
כסף משנה
5.
If locusts consumed [a field] in its midst or ants destroyed it, should one plow the portion that was consumed,11If, however, one does not plow the consumed portion, it is not considered as a separation (Menachot 71b). it is considered to be a separation.

הלכה ו
הַזּוֹרֵעַ בָּהָר שֶׁאֵינוֹ כֻּלּוֹ שָׁוֶה אֶלָּא יֵשׁ בּוֹ תִּלִּים גְּבוֹהִים וּמְקוֹמוֹת מְקוֹמוֹת עֲמֻקּוֹת אַף עַל פִּי שֶׁאֵינוֹ יָכוֹל לַחֲרשׁ אוֹתוֹ כֻּלּוֹ וּלְזָרְעוֹ כְּאַחַת אֶלָּא נֶחְרָשׁ הַמָּקוֹם הַגָּבוֹהַּ בִּפְנֵי עַצְמוֹ וְהַנָּמוּךְ בִּפְנֵי עַצְמוֹ הֲרֵי זֶה כְּשָׂדֶה אַחַת וּמַנִּיחַ פֵּאָה אַחַת בְּסוֹף הָהָר עַל כָּל הָהָר:
כסף משנה
6.
[The following law applies when one] sows [crops] on a mountain [slope] that is not level, but instead has knolls and hollows. Even though he cannot plow it all at once and sow it all at once, but instead must plow the knolls by themselves and the hollows by themselves, it is considered as a single field. He should leave one portion of pe'ah at the end of the mountain for the entire mountain.12This follws the second interpretation given by the Rambam in his Commentary to the Mishnah (Pe'ah 2:2).

הלכה ז
מַדְרֵגוֹת שֶׁהֵן גְּבוֹהוֹת עֲשָׂרָה טְפָחִים נוֹתֵן פֵּאָה מִכָּל אַחַת וְאַחַת. וְאִם הָיוּ רָאשֵׁי שׁוּרוֹת מְעֹרָבִים נוֹתֵן מֵאַחַת עַל הַכּל. הָיוּ פָּחוֹת מֵעֲשָׂרָה אַף עַל פִּי שֶׁאֵין רָאשֵׁי הַשּׁוּרוֹת מְעֹרָבִין נוֹתֵן מֵאַחַת עַל הַכּל. הָיָה סֶלַע עַל פְּנֵי כָּל הַשָּׂדֶה. אִם עוֹקֵר הוּא אֶת הַמַּחְרֵשָׁה מִצַּד זֶה וְנוֹתְנָהּ מִצַּד זֶה מַפְסִיק. וְאִם לָאו אֵינוֹ מַפְסִיק:
כסף משנה
7.
[The following laws apply when one sows crops on] terraced land. [When each terrace] is ten handbreadths higher than the other, one should leave pe'ah [separately] for each terrace. If the heads of the rows are joined together, he should leave one portion of pe'ah for the entire area. If they were less than ten handbreadths higher, he should leave one portion of pe'ah even if the heads of the rows are not joined together.
[The following rules apply] if there was a rock covering the surface of the entire field. If he must lift up the plow from one side and place it on the other side, it is considered an interruption.13Since the rock divides the field, it is considered as two separate entities. Hence, he must leave pe'ah for each portion of the field individually. The commentaries question why this instance is different than the terraces that are less than ten handbreadths higher than each other mentioned in the first clause, for there too, he must lift the plow and move it to the side while plowing. The Kessef Mishneh explains that the terraces are different because they can be sown and hence they appear as a single field, while the rock cannot be sown. If not, it is not considered an interruption.

הלכה ח
הַזּוֹרֵעַ שָׂדֶה שֶׁיֵּשׁ בָּהּ אִילָנוֹת אַף עַל פִּי שֶׁהִיא מַלְבְּנוֹת מַלְבְּנוֹת בֵּין הָאִילָנוֹת וְאֵין כָּל הַזֶּרַע מְעֹרָב נוֹתֵן פֵּאָה אַחַת לְכָל הַשָּׂדֶה. שֶׁדָּבָר יָדוּעַ שֶׁשָּׂדֶה אַחַת הִיא וּמִפְּנֵי מְקוֹם הָאִילָנוֹת נֶחְלַק הַזֶּרַע:
כסף משנה
8.
When a person sows a field that has trees - even though he sows it in squares14The term the Rambam uses literally means "the mold used to make bricks." That term is employed because the squares resemble such a mold [the Rambam's Commentary to the Mishnah (Pe'ah 3:1). between the trees and thus the entire crop does not come together as one - he should give one portion of pe'ah for the entire field. For it is known that it is one field; it is only the place of the trees that causes the crop to be divided.15I.e., had there not been trees in the field, the entire field would have been sown as a single entity. It was the presence of the trees alone that caused him to divide it. Thus since it is essentially one field, he leaves one portion of pe'ah.

הלכה ט
בַּמֶּה דְּבָרִים אֲמוּרִים בְּשֶׁהָיוּ הָאִילָנוֹת כָּל עֲשָׂרָה בְּתוֹךְ בֵּית סְאָה. אֲבָל אִם הָיוּ כָּל עֲשָׂרָה אִילָנוֹת בְּיוֹתֵר מִבֵּית סְאָה הֲרֵי זֶה נוֹתֵן פֵּאָה מִכָּל מַלְבֵּן וּמַלְבֵּן. שֶׁהֲרֵי הָאִילָנוֹת מְרֻחָקִים הַרְבֵּה וְלֹא מִפְּנֵי הָאִילָנוֹת זָרַע מַלְבְּנוֹת מַלְבְּנוֹת:
כסף משנה
9.
When does the above apply? When all ten trees were located in an area in which a se'ah [of grain can be sowed].16An area 50 cubits by 50 cubits (Hilchot Shabbat 16:3; Hilchot Kilayim 4:7). If, however, all ten trees were located in an area larger than that in which a se'ah [of grain can be sowed], he should leave pe'ah from every square separately. For the trees are far apart and they did not cause him to sow the field in squares.17Instead, he considered each block separate for other reasons. Hence, pe'ah should be left for each one individually. The Ra'avad takes issue with the Rambam, basing his objections on the Jerusalem Talmud (Pe'ah 3:1). The Radbaz and the Kessef Mishneh explain that the Rambam had a different version of the Jerusalem Talmud and that accounts for the difference between their positions. They also maintain that the Rambam's position is sounder logically, for the larger the field, the more likely it is that each separate block should be considered an independent field.

הלכה י
וְכֵן מַלְבְּנוֹת הַבְּצָלִים שֶׁבֵּין הַיָּרָק נוֹתֵן פֵּאָה אַחַת לְכָל הַבְּצָלִים. וְאַף עַל פִּי שֶׁהַיָּרָק מַבְדִּיל בֵּינֵיהֶן וּמְשִׂימָם מַלְבְּנוֹת מַלְבְּנוֹת:
כסף משנה
10.
Similarly, if squares of onions [grow] between vegetables,18Needless to say, there must be a distinction between the vegetables and the onions so that the laws of kilayim, mixed species, are not violated. one should leave a single portion of pe'ah for all the onions even though the vegetables grow between them and cause them to appear as separate squares.19In this instance as well, the physical separation does not cause the squares to be considered as separate fields. The Radbaz suggests that the reason the principle stated in Halachah 4 - that if another crop separates between two plantings of one crop, separate portions of pe'ah should be left - does not apply here is that there is no obligation to leave pe'ah for vegetables.

הלכה יא
שָׂדֶה שֶׁכֻּלָּה זְרוּעָה מִין אֶחָד וְכֵיוָן שֶׁהִתְחִילוּ בָּהּ מְקוֹמוֹת לִיבַשׁ עָקַר אוֹ תָּלַשׁ מַה שֶּׁיָּבַשׁ מִכָּאן וּמִכָּאן עַד שֶׁנִּשְׁאַר הַלַּח מְפֹרָד מַלְבְּנוֹת מַלְבְּנוֹת מְרֻחָקוֹת זוֹ מִזּוֹ. אִם הָיָה דֶּרֶךְ בְּנֵי אָדָם שָׁם לִזְרֹעַ מֵאוֹתוֹ הַמִּין עֲרוּגוֹת עֲרוּגוֹת כְּגוֹן שֶׁבֶת אוֹ חַרְדָּל הֲרֵי זֶה מַנִּיחַ פֵּאָה מִכָּל מַלְבֵּן וּמַלְבֵּן. שֶׁהָרוֹאֶה אוֹמֵר עֲרוּגוֹת עֲרוּגוֹת נִזְרְעוּ. וְאִם הָיָה מִין אֶחָד שֶּׁזּוֹרְעִין אוֹתוֹ שָׂדוֹת כְּגוֹן תְּבוּאָה וְקִטְנִיּוֹת נוֹתֵן אַחַת לַכּל:
כסף משנה
11.
[The following laws apply when a person] sowed an entire field with one crop, but when certain places in the field began to dry out, he uprooted or pulled out the crops that had dried out on either side until the fresh crops appeared as separate blocks. If it was customary for people to sow that crop in individual rows, e.g., dill or mustard seed,20The commentaries note that the Rambam's statements here appear to contradict his statement in Hilchot Kilayim 1:9, in which he states that it is customary to sow entire fields of mustard seed. They are, however, reinforced by his statements in Hilchot Kilayim 3:18. he should leave pe'ah for each individual square, for an observer would say: "It was planted in separate rows."21And thus each square is considered as a separate field, requiring its own pe'ah. If it was a species that was usually sown throughout an entire field, e.g., grain or legumes, he should leave one portion of pe'ah for the entire [field].22For the whole field will be considered as a single entity.

הלכה יב
בַּמֶּה דְּבָרִים אֲמוּרִים כְּשֶׁהָיָה יָבֵשׁ מִכָּאן וְיָבֵשׁ מִכָּאן וְלַח בָּאֶמְצַע. אֲבָל לַח מִכָּאן וּמִכָּאן וְיָבֵשׁ בָּאֶמְצַע מַנִּיחַ מִן הַיָּבֵשׁ בִּפְנֵי עַצְמוֹ וּמִן הַלַּח בִּפְנֵי עַצְמוֹ:
כסף משנה
12.
When does the above apply? When there were dried out portions on either side and the fresh portion in the center.23For then it appears as a single field. If, however, the fresh portions are on either side and the dried out portion is in the center, he should leave pe'ah separately for the dried out portion and the fresh portions.24For then each portion appears as a separate field. The Ra'avad disputes the Rambam's ruling based on his interpretation of the Jerusalem Talmud (Pe'ah 3:1). The Radbaz and the Kessef Mishneh explain the Rambam's position within the context of that passage.

הלכה יג
שָׂדֶה שֶׁזְּרָעָהּ בְּצָלִים אוֹ פּוֹלִים אוֹ אֲפוּנִים וְכַיּוֹצֵא בָּהֶן וְהָיָה בְּדַעְתּוֹ לִמְכֹּר מִקְצָתָן לַחִין בַּשּׁוּק וּמַנִּיחַ מִקְצָת הַשָּׂדֶה יָבֵשׁ וְיַעֲשֶׂה מִמֶּנּוּ גֹּרֶן. חַיָּב לְהַנִּיחַ פֵּאָה לְזֶה שֶׁמּוֹכֵר לַח בִּפְנֵי עַצְמוֹ וְלָזֶה שֶׁקּוֹצֵר אוֹתוֹ יָבֵשׁ בִּפְנֵי עַצְמוֹ:
כסף משנה
13.
[The following law applies when a person] sowed a field with onions, beans, peas,25The commentaries note that there are some species of peas that are considered vegetables - and for which pe'ah need not be left - and others are considered as legumes. Here we are speaking about a species that are considered legumes. or the like. If he had the intent to sell some of the fresh produce in the marketplace and leave part of the field to dry out and to be put aside in storage, he is obligated to leave pe'ah separately for both the portion he sells and the portion he harvests for storage.26For each is considered as a separate harvest. The Radbaz explains that even if the person does not divide the field into separate portions, but rather harvests a small amount from each place both times, the two harvests are considered as separate. The difference in the time when they are harvested and the purpose for which they are harvested distinguishes them from each other. For [produce sold in] the market and produce set aside in storage are considered as two separate types.

הלכה יד
הַזּוֹרֵעַ אֶת שָׂדֵהוּ מִין אֶחָד אַף עַל פִּי שֶׁהוּא עוֹשֵׂהוּ שְׁתֵּי גֳּרָנוֹת מַנִּיחַ פֵּאָה אַחַת. זְרָעָהּ שְׁנֵי מִינִים אַף עַל פִּי שֶׁהוּא עוֹשֶׂה אוֹתָהּ גֹּרֶן אַחַת נוֹתֵן פֵּאָה לְמִין זֶה בִּפְנֵי עַצְמוֹ וּפֵאָה לְמִין זֶה בִּפְנֵי עַצְמוֹ:
כסף משנה
14.
When a person sows his field with one species, he should leave one portion of pe'ah even though he collects the crops in two grain heaps.27This halachah is speaking about a situation where a person transgressed and harvested his entire field and then desires to correct his actions by leaving pe'ah. The Radbaz states that the Rambam's ruling applies even if he makes these grain heaps at separate times. If he sows two species, even though he makes only one grain heap, he should leave pe'ah for each species separately.

הלכה טו
זָרַע שְׁנֵי זְרָעִים מִמִּין אֶחָד כְּגוֹן שֶׁזְּרָעָהּ שְׁנֵי מִינֵי חִטִּים אוֹ שְׁנֵי מִינֵי שְׂעוֹרִים. אִם עֲשָׂאָן גֹּרֶן אַחַת נוֹתֵן פֵּאָה אַחַת. שְׁתֵּי גֳּרָנוֹת נוֹתֵן שְׁתֵּי פֵּאוֹת. וְדָבָר זֶה הֲלָכָה לְמשֶׁה מִסִּינַי:
כסף משנה
15.
[The following law applies when a person] sows two types of the same species, e.g., he sows two types of wheat28In his Commentary to the Mishnah (Pe'ah 2:5), the Rambam gives examples: "thin kernels or thick kernels, red wheat and green wheat." or two types of barley. If he stores them in one grain heap, he should leave one portion of pe'ah. If he stores them in two grain heaps, he should leave separate portions of pe'ah. This is a halachah communicated by Moses from Sinai.29I.e., a point from the Oral Tradition for which there is no direct source in the Written Law.

הלכה טז
הָאַחִין שֶׁחָלְקוּ נוֹתְנִין שְׁתֵּי פֵּאוֹת. חָזְרוּ וְנִשְׁתַּתְּפוּ נוֹתְנִין פֵּאָה אַחַת. הַשֻּׁתָּפִין שֶׁקָּצְרוּ חֲצִי הַשָּׂדֶה וְאַחַר כָּךְ חָלְקוּ. זֶה שֶׁלָּקַח הַקָּצִיר אֵינוֹ מַפְרִישׁ כְּלוּם. וְזֶה שֶׁלָּקַח הַקָּמָה מַפְרִישׁ עַל הַחֵצִי שֶׁלָּקַח בִּלְבַד. חָזְרוּ וְנִשְׁתַּתְּפוּ וְקָצְרוּ הַחֵצִי הָאַחֵר בְּשֻׁתָּפוּת. כָּל אֶחָד מֵהֶן מַפְרִישׁ מֵחֶלְקוֹ שֶׁבַּקָּמָה עַל חֵלֶק חֲבֵרוֹ שֶׁבַּקָּמָה אֲבָל לֹא עַל הַחֵצִי שֶׁנִּקְצַר:
כסף משנה
16.
When brothers have divided [the estate they inherited], they should leave pe'ah separately. If later30Before the harvesting of the field (Radbaz). they joined together in partnership, they should leave only one portion of pe'ah.31As is the law concerning partners (Chapter 2, Halachah 3). When partners who have harvested half of a field break up the partnership, [one taking the grain that was harvested already and one taking the standing grain,] the one who took the grain that was harvested does not separate anything32For at the time the grain was harvested, there was no obligation to separate pe'ah from it, for the obligation to separate pe'ah applies to the standing grain (Chapter 2, Halachah 4). Hence the partner who receives the harvested grain considers the situation analogous to that of a person who harvests half a field and then sells the remainder, in which instance, the purchaser - i.e., the second partner - is obligated to separate pe'ah for the entire field (ibid.:5). and the one who took the standing grain is required to separate only for the half which he took.33The rationale is that the second partner does not accept that rationale. Instead, he claims that we apply the principle of bereirah - that retroactively, it is considered as if the two partner's portions were divided from the outset. Thus from the outset, he was never required to do more than divide pe'ah from his individual portion.
One might protest that in this situation, the outcome is that the poor people do not receive their pe'ah. Indeed, that is the case. Our Sages did not resolve whether the principle of bereirah should be applied or not. Hence, each partner can claim that the responsibility for leaving pe'ah for the first half of the field lies on the other partner and not on him. Neither is not obligated to pay from his own funds, because in financial matters, we follow the principle: When one desires to expropriate money from a colleague, the burden of proof is upon him.
If, afterwards, they reestablished their partnership34Before harvesting the second half of the field, agreeing that each one received half of the grain that was harvested and half of the grain to be harvested (Kessef Mishneh). and harvested the second half as partners, either one may separate [pe'ah] for his colleague's portion of the standing grain from his own portion of the standing grain,35Since they reestablished their partnership, one pe'ah can be left for the remaining portion of the field. Either of the partners may do this, leaving a portion for his own grain and that of his partner. He does not have to do this for the grain in the first part of the field, as the Rambam continues to explain. but not for the portion that was already harvested.36Since there was no pe'ah required to be left for it originally, there is no requirement to leave pe'ah for it now.

הלכה יז
שָׂדֶה שֶׁהִגִּיעַ חֶצְיָהּ עַד שְׁלִישׁ וְחֶצְיָהּ לֹא הִגִּיעַ. וְהִתְחִיל וְקָצַר בְּחֵצִי שֶׁהִגִּיעַ חֶצְיוֹ וְאַחַר כָּךְ הֵבִיאָה כֻּלָּהּ שְׁלִישׁ וְאַחַר כָּךְ גָּמַר הַחֵצִי הָרִאשׁוֹן שֶׁהִגִּיעַ בַּתְּחִלָּה. מַפְרִישׁ מִן הָרִאשׁוֹן עַל הָאֶמְצָעִיִּים וּמִן הָאֶמְצָעִיִּים עַל הָרִאשׁוֹן וְעַל הָאַחֲרוֹן:
כסף משנה
17.
[There are situations in which pe'ah may be given from different parts of a field for other parts of the same field that were harvested afterwards. For example, the grain of] half of a field ripened to a third of its maturity and half did not ripen to that extent. [The owner] harvested half of the portion that reached maturity.37And did not leave pe'ah for this harvest although he was obligated to do so. Afterwards, the remainder of the field ripened to one third and then he completed the harvest of the first half that reached [a third of its maturity] previously. He may separate [pe'ah] from [the crops] harvested first for the middle portion38I.e., the crops that ripened initially, but were not harvested. Since they ripened at the same time as those which were harvested first, they can be included in the same pe'ah. and from the middle portion on the first portion39As above, since they ripened at the same time, they could be considered a single field. The Kessef Mishneh states that this is preferable, because as mentioned previously, pe'ah should be left from standing grain for the portions harvested previously. and on the last portion.40Since this portion ripened before the second portion was harvested, it and the second portion could be considered as part of a single field and one measure of pe'ah would be sufficient for them both.

הלכה יח
הַמּוֹכֵר מְקוֹמוֹת מְקוֹמוֹת מִשָּׂדֵהוּ לַאֲנָשִׁים הַרְבֵּה. אִם מָכַר כָּל הַשָּׂדֶה כָּל אֶחָד וְאֶחָד נוֹתֵן פֵּאָה אַחַת מֵחֶלְקוֹ שֶׁלָּקַח. וְאִם הִתְחִיל בַּעַל הַשָּׂדֶה לִקְצֹר וּמָכַר מִקְצָת וְשִׁיֵּר מִקְצָת. בַּעַל הַשָּׂדֶה נוֹתֵן פֵּאָה הָרְאוּיָה לַכּל. שֶׁכֵּיוָן שֶׁהִתְחִיל לִקְצֹר נִתְחַיֵּב בַּכּל. וְאִם מָכַר תְּחִלָּה מַפְרִישׁ הַלּוֹקֵחַ עַל מַה שֶּׁלָּקַח וּבַעַל הַשָּׂדֶה עַל מַה שֶּׁשִּׁיֵּר:
כסף משנה
18.
[The following laws apply when a person] sells separate portions in his field to different people. If he sold his entire field, each one of the purchasers should leave pe'ah for the portion that he purchased.41For each portion of the field is considered as a separate entity. If the owner of the field had begun to harvest his field and sold a portion and retained a portion, the owner of the field should leave [the amount of] pe'ah appropriate for the entire field. [The rationale is that] since he began harvesting [the field] he became obligated to [separate pe'ah for] the entire [field].42Chulin 138a derives this from the exegesis of Leviticus 23:22: "When you reap the harvest of your land" which implies that the obligation to leave pe'ah begins when on starts reaping. If he sold [the portions of the field] before [he began harvesting], the purchaser should separate [pe'ah] for the portion he purchased and the owner for the remainder.

הלכה יט
שְׂדֵה אִילָן אֵין מַפְסִיק בָּהּ אֶלָּא גָּדֵר גָּבוֹהַּ הַמַּבְדִּיל בֵּין הָאִילָנוֹת. אֲבָל אִם הָיָה הַגָּדֵר מַבְדִּיל מִלְּמַטָּה וְהַבַּדִּים וְהַפְּאֵרוֹת מְעֹרָבִין מִלְּמַעְלָה וְנוֹגְעִין בַּגָּדֵר עַל גַּבּוֹ הֲרֵי זֶה כְּשָׂדֶה אַחַת וְנוֹתֵן פֵּאָה לַכּל:
כסף משנה
19.
Only a high fence that separates between [the branches of] the trees divides an orchard with regard [to the laws of pe'ah]. If, however, the fence separates on a lower level, but the branches and the trellises are intermingled above and touch the top of the fence, the orchard is considered a single entity and [only] one portion of pe'ah should be given.43Based on the Rambam's Commentary to the Mishnah (Pe'ah 2:3), it appears that if trees are separated by a fence that is ten handbreadths high, they are considered as in separate fields unless their branches are intermingled above. If their branches are intermingled above, they are considered as one field, regardless of the height of the fence.

הלכה כ
שְׁנַיִם שֶׁלָּקְחוּ אִילָן אֶחָד נוֹתְנִין מִמֶּנּוּ פֵּאָה אַחַת. לָקַח זֶה צְפוֹנוֹ וְזֶה דְּרוֹמוֹ זֶה נוֹתֵן פֵּאָה לְעַצְמוֹ וְזֶה נוֹתֵן פֵּאָה לְעַצְמוֹ:
כסף משנה
20.
When two people purchased one tree [in partnership], they should leave one portion of pe'ah from it. If one purchased the northern side [of a tree] and the other purchased [the southern side], each one should leave pe'ah individually.44Since they are not partners, the portion of each one is considered individually.

הלכה כא
הֶחָרוּבִין כָּל שֶׁאָדָם עוֹמֵד בְּצַד חָרוּב זֶה וַחֲבֵרוֹ עוֹמֵד בְּצַד חָרוּב זֶה וְרוֹאִין זֶה אֶת זֶה הֲרֵי הֵן כֻּלָּן שָׂדֶה אַחַת וּפֵאָה אַחַת לְכֻלָּן. הָיוּ שְׁנֵי הַצְּדָדִין רוֹאִין אֶת הָאֶמְצָעִיִּים וְאֵין הַצְּדָדִים רוֹאִין זֶה אֶת זֶה מַפְרִישׁ מִצַּד אֶחָד מִן הָרִאשׁוֹנִים עַל הָאֶמְצָעִיִּים וּמִן הָאֶמְצָעִיִּים עַל הָרִאשׁוֹנִים. אֲבָל לֹא יַפְרִישׁ מִצַּד זֶה עַל הַצַּד הָאַחֵר:
כסף משנה
21.
[The following laws apply to] carob trees:45I.e., in contrast to other trees that are separated by fences, different laws apply with regard to carobs (Rav Yosef Corcus). The Ra'avad offers a different interpretation of this law.
The Ra'avad explains that carobs and olives (mentioned in the following halachah) are governed by different laws than other trees because they are tall and the branches of one tree are likely to become intermingled with another. The Radbaz does not accept this explanation, because palm trees are taller than carobs and olives and pear trees are also taller and more likely to be intermingled. He explains instead that these trees are singled out, because they are extremely common in Eretz Yisrael.
Whenever one person stands next to one carob tree and his colleague stands next to another carob tree and they can see each other, [the trees] are considered as in one field and one portion of pe'ah should be left for them.
[Different rules apply] if, however, those on the extremes can see those in the center, but those on the extremes cannot see each other, he may separate from those on the extremes for those on the center and from those in the center for those on the extremes.46Since they can see each other, the principles stated in the first clause apply. He may not, however, separate from those on one extreme for those on the other extreme.47Because they cannot see each other.

הלכה כב
הַזֵּיתִים כָּל מַה שֶּׁיֵּשׁ מֵהֶן בְּרוּחַ אַחַת מֵרוּחוֹת הָעִיר כְּגוֹן זֵיתִים שֶׁיֵּשׁ בְּמַעֲרַב הָעִיר כֻּלָּן אוֹ בְּמִזְרָחָהּ הֲרֵי הֵן כְּשָׂדֶה אַחַת וּפֵאָה אַחַת לְכֻלָּן:
כסף משנה
22.
[The following laws apply to] olive trees: All the trees on one of the sides of a city, e.g., all of the olive trees on the entire western side or the entire eastern side of a city are considered as being from one field and one portion of pe'ah should be left for all of them.

הלכה כג
הַבּוֹצֵר אֶת מִקְצָת כַּרְמוֹ מִכָּאן וּמִכָּאן כְּדֵי לְהָקֵל מֵעַל הַגֶּפֶן עַד שֶׁיִּמְצְאוּ שְׁאָר הָאֶשְׁכּוֹלוֹת רֶוַח וַיּוֹסִיפוּ הוּא הַנִּקְרָא מֵדֵּל. וּכְבָר בֵּאַרְנוּ שֶׁהַבּוֹצֵר מֵרוּחַ אַחַת אֵינוֹ מֵדֵּל וּלְפִיכָךְ נוֹתֵן מִן הַנִּשְׁאָר פֵּאָה הָרְאוּיָה לַכּל. וְאַף עַל פִּי שֶׁבָּצַר לַשּׁוּק. אֲבָל אִם הֵדֵּל לִמְכֹּר בַּשּׁוּק אֵינוֹ נוֹתֵן פֵּאָה לְזֶה שֶׁהֵדֵּל. הֵדֵּל לְהָבִיא בְּבֵיתוֹ נוֹתֵן מִן הַנִּשְׁאָר שֶׁהִנִּיחַ לִדְרֹךְ פֵּאָה אַחַת הָרְאוּיָה לַכּל:
כסף משנה
23.
A person who harvests a portion of his vineyard from either side in order to lessen [the demand] on the vines so that the other clusters will have more room and increase in size is called one who reduces.48The owner is not obligated to leave pe'ah for the fruit harvested for this reason, as the Rambam proceeds to explain. We already explained49Chapter 2, Halachah 6. that a person who harvests from one side is not considered as one who reduces. Therefore he must leave the amount of pe'ah appropriate for the entire field even though he harvested [with the intent of selling the grapes in] the marketplace. If, however, he reduces [the produce on the vines with the intent of] selling [the produce] in the marketplace, he should not leave pe'ah for the produce that he took off.50For the primary reason he harvested it was to diminish the pressure on his vines. Since he is not interested in the harvest per se, he is not obligated to leave pe'ah. [Nevertheless,] if he reduces [the produce on the vines with the intent of] taking it home,51The fact that he takes the produce home demonstrates that his harvest is a calculated act and hence requires pe'ah. he should leave the amount of pe'ah appropriate for the entire field from [the grapes] he left to be trodden for the vat.

זרעים הלכות מתנות עניים פרק ג
Zeraim Aniyim Chapter 3