הלכה אויף דברים 24:19

And so it is with peret [separated fruit] that fell from the vine at the time of harvesting and with olélot [malformed grape clusters], as it is said, (Lev. 19:10) You shall not pick your vineyard bare [te'olél] or gather the fallen fruit [uferet] of your vineyard; you shall leave them for the poor and the stranger. So also with one who stacks sheaves and has forgotten a sheaf in the field. This person may not recover it, as it is said, (Deut. 24:19) And overlook a sheaf in the field, do not turn back to get it. If one does transgress [the negative mitzvah against picking up a forgotten sheaf] and gleans and even grinds and bakes, this one still must give to the poor, as it is said, (Deut. 24:19) It shall go to the stranger, the fatherless, and the widow. This is a positive mitzvah. Thus you learn that all these mitzvot are negative which are transformed into positive mitzvot, and if one does not fulfill a positive mitzvah, one deserves punishment.³Each one of these verses is two-fold; one part corresponds to the prohibition against gleaning or picking all of a crop while the other part is the injunction to give food to the poor. Each one of the gifts for the poor involves two acts: one of self-restraint and one of giving.

All of these gifts for the poor as they are in the Torah only apply to the Land of Israel, like gift offerings and tithes. Thus Scripture says, (Lev. 19:9, 23:22) When you reap the harvest of your land, [and] (Deut. 24:19) When you reap the harvest in your field. [But] it has already been explained in the Talmud¹⁴See Babylonian Talmud Chullin 137b. that the category of péah applies outside of the Land of Israel from rabbinic law, and it appears to me that it makes sense for the remaining types of gifts for the poor to all apply to outside of the Land of Israel from rabbinic law as well.¹⁵See Mishnah Kiddushin 1:9. In this law as well as the next, Maimonides makes a distinction between laws that are from the Torah itself and rabbinic rulings. While laws from the Torah are more directly authoritative, the laws of the rabbis rest on the authority of a tradition of sacred interpretation and were considered just as binding as the laws of the Torah. Indeed, some rabbinic laws carried very severe punishments for their transgression to discourage challenging their authority. The rabbinic law seeks to clarify the intent of the Torah, filling in the gaps that the Torah does not make clear. In this instance, the location of where these laws are in force in the Jewish community and the minimum amount that needed to be given are details lacking in the Torah that the rabbis fill in.

If one harvested and there remained one stalk that was not harvested but all around it was harvested, if its end was even with the standing grain that was on the side and it is possible that it will be harvested with the standing grain, then this is the owner of the field's, and if not [that is, it is not close enough to the standing grain to be harvested with it when the reapers come through again,] then this belongs to the poor.⁶⁵See Mishnah Péah 5:2. These will be harvested in the normal course of things.