When you reap the harvest in your field and overlook a sheaf in the field, do not turn back to get it; it shall go to the stranger, the fatherless, and the widow-in order that the L-RD your God may bless you in all your undertakings.

When you beat down the fruit of your olive trees, do not go over them again; that shall go to the stranger, the fatherless, and the widow. When you gather the grapes of your vineyard, do not pick it over again; that shall go to the stranger, the fatherless, and the widow. Always remember that you were a slave in the land of Egypt; therefore do I enjoin you to observe this commandment. (Deuteronomy 24:19-21; JPS translation)

Yitzhak Heinemann, in his book Ta‘amei Ha-Mitzvot be-Sifrut Yisrael, (sixth edition, [Jerusalem, 1993], p. 17), cites these mitzvoth as an example of commandments whose reasons are manifest. (Nechama Leibowitz, Iyyunim be-Sefer Devarim [Jerusalem, 1994], p. 228=Studies in Devarim, translated and adapted from the Hebrew by Aryeh Newman, [Jerusalem, 1980], p, 244, cites Prof. Heinemann’s remarks.) Heinemann points out that it is impossible to perform certain mitzvoth without automatically thinking of the purpose of the commandment. In our case, already in an earlier book of the Torah (Leviticus 19:10), the reason for the performance of leqet shikhhah and pe’ah is mentioned, as gifts to the poor.

Heinemann adds the notion that in ancient times, a prevalent custom existed to leave gleanings of the field to demons. The Torah, therefore, goes out of the way to stress that the reason why the Israelites should know what the true, ethical reason for the law is. (This notion is cited in the JPS Torah commentary to Deuteronomy, and see ibid., p. 390, n.71, where an article by T. Canaan, “Plant-Lore in Palestinian Superstition,” Journal of the Palestinian Oriental Society 8 (1928), pp. 140-41, is cited, quoting the customs of the Bedouins and others. Some places retained a custom of “burying the last sheaf in the same place where it had been reaped, while the Mohammedean creed is recited. This offering to the unseen powers living in the field is made in the hope that the supernatural beings, whose property has been taken away, will be appeased by the offering of a part and grant a prosperous crop in the following year.” The point of Prof. Heinemann is that the Torah’s goal was to eradicate such superstitious beliefs from benei yisrael.

The claim that the reason for a law in the Torah is to uproot a practice that was performed by pagans for idolatrous purposes was maintained by the Rambam in a host of cases. Rambam, for example, wrote that the reason for many a mitzvah is to uproot the false belief in the existence of demons [shedim or jinn] that possessed magical powers. Rambam writes as follows:

Know that the Sabians held that blood was most unclean, but in spite of this used to eat of it, deeming that it was the food of the devils and that, consequently, whoever ate it fraternized with the jinn so that they came to him and let him know future events- according to what the multitude imagine concerning the jinns. There were, however, people there who considered it a hard thing to eat of blood, this being a thing abhorrent to the nature of man. Accordingly, they used to slaughter an animal, collect its blood in a vessel or in a ditch, and eat the flesh of this slaughtered animal close by its blood. In doing this they imagined that the jinn partook of this blood, this being their food, whereas they themselves ate the flesh. In this way fraternization was achieved, because all ate at the same table and in one and the same gathering. Consequently, as they deemed, these jinn would come to them in dreams, inform them of secret things, and be useful to them. All these were opinions that were in those times followed, favored, and generally accepted; the multitude did not doubt of their truth. Thereupon the Law, which is perfect in the opinion of those who know it, began to put an end to these inveterate diseases. Consequently, it prohibited the eating of blood, putting the same emphasis on this prohibition as on the prohibition against idolatry. For He, may He be exalted, says I will set My face against that soul that eats blood (Leviticus 17:10), and so on, just as He has said with regard to him who gives of his seed to Moloch (Lev. 20:4-6) I will even set My face against that soul, and so on. No such text occurs regarding a third commandment other than the prohibition of idolatry and of eating of blood. That is so because the eating of blood led to a certain kind of idolatry, namely, to the worship of the jinn. [Scripture pronounced blood to be pure and turned it into a means of purification for those who came near it: And sprinkle it upon Aaron, and upon his garments, and so on; and he and his garments shall be hallowed (Exodus 29:21). It also commands the sprinkling of blood upon the altar and cause the whole act of worship to consist in pouring it out there, not in gathering it together: And I have given it to you upon the altar to make atonement (Leviticus 17:11). There it was poured out according to what it says: And all the remaining blood shall he pour out (Lev. 4:18); and it says: And the blood of your sacrifices shall be poured out upon the altar of the L-RD your God (Deuteronomy 12:27). And it commands pouring the blood of every beast that is slaughtered, even if it was not offered up in sacrifice; it says: You shall pour it out upon the earth as water (Deut. 12:16 and 12:24).Thereupon it forbids gathering around the blood and eating there, saying You shall not eat round the blood (Lev. 19:26).When they continued in their disobedience and in following the generally accepted usage in which they had been brought up of fraternizing with the jinn through eating around the blood, He may he be exalted, commanded that no meat of desire be eaten at all in the desert, but that all be offered up as peace offerings. It is clear to us that the reason for this is that the blood should be poured out upon the altar and that people should not gather around it. Accordingly, it says, To the end that the children of Israel may bring, and so on. And they shall no more offer their sacrifices unto the devils [se‘irim], and so on (Lev. 17:5 and 7). But the matter of wild beasts and of birds still remained to be settled, for wild beasts may not be sacrificed at all and birds may not be offered as peace offerings. Consequently, He, may He be exalted, commanded that when any of t he wild beasts or birds whose flesh it is permitted to eat has been slaughtered, its blood should be covered up with dust (Lev. 17:13) so that people should not gather to eat around it [the blood]. Thus the aim was achieved and the purpose realized: namely, to break the brotherhood between those truly possessed [i.e., madmen] and their jinn….

Know that the meat of desire was only forbidden in the desert. For it was one of the generally accepted opinions that the jinn lived in deserts and held converse and appeared there, but did not appear in cities and cultivated places; so that whenever a townsman wished to do something in the ways of this insanity, he had to go from the city to the secret and to isolated places. Therefore, the meat of desire became permitted after the entry into the land [of Canaan]. (See Guide of the Perplexed, Pines ed. [Chicago, 1963], pp. 585-85.)

The attitude of R. Moshe ben Nahman (Ramban) towards this particular Maimonidean notion is complex. Although in many cases Ramban strongly rejects the methodology of Rambam in his ta‘amei ha-mitzvoth, in this case Ramban, in his comments to Leviticus 17:11 cites the aforementioned Moreh Nevukhim passage, and writes are they are words that are “sensible in themselves” (meyushavim) . However, he also argues that the Leviticus text, which consistently mentions for the life of all flesh is blood (Lev. 17:14) implies that the reason to prohibit blood expresses something more than the desire to uproot an idolatrous practice. Nonetheless, in his commentary to Deuteronomy 12:23-25, Ramban, used Rambam’s idea to explain a halakhic feature of the mitzvah to cover the blood of a slaughtered animal (kisui ha-dam-Leviticus 17:13): why does this mitzvah, one that according to the Rambam were commanded in order to eradicate the false beliefs and practices associated with the jinn, only apply to birds and wild animals but not to domesticated animals? Ramban writes that generally, birds and wild animals would be generally slaughtered in the forests, and the blood would be left there, while the carcass of the bird or wild animal would be brought home to be eaten. Consequently, the blood of birds or wild animals would be left to be part of a rite with the jinn. On the other hand, domesticated animals would be generally slaughtered in one’s own field or house (i.e., the place where one prepares food), and not in the wild, and consequently their blood would not be used for any participatory rites with the jinn. Consequently, once the children of Israel entered the Land of Israel and were allowed to eat “basar ta’avah,” the “flesh of their desire,” i.e., meat of domesticated animals for their own consumption and not for sacrificial purposes, there would be no need for a mitzvah of kisui ha-dam with the blood of a slaughtered behemah.

This Ramban is striking for, among other points, explaining that the original reason for the distinction between cases where there is an obligation of kisui ha-dam and where there is not grounded in a question of location, which itself is a function of the prevalence of the rites regarding demons, and not a function of the nature of the animals themselves (birds and wild animals as opposed to domesticated animals). (To be sure, the point may be implicit in the Maimonidean passage quoted above, but Ramban makes it explicit. Another distinction between the Rambam’s viewpoint and that of the Ramban concerns the reality or lack thereof of the jinn. Rambam clearly rejects the reality of any such beings. They are all figments of one’s imagination. Ramban, on the other hand, accepts their reality but understands that the Torah only forbids worshipping them or trying to communicate with them).

Thus, at the end of the day, Prof. Heinemann’s point regarding the ancient custom concerning shedim and leqet, shikhah and pe’ah can be viewed as an extension of the methodology of the Rambam to another case, namely, leaving gleanings for the poor. The Torah uproots the popular superstition in order to guide the Israelite people to a refined notion of monotheism.

Nechama Leibowitz (ad loc.) pointed out a difficulty with the view that the reason for the Torah’s mitzvoth of leqet shikhhah and pe’ah is exclusively one of gifts for the poor. Although one can grant that the essence of the mitzvoth of leqet shikhhah and pe’ah (and peret and ollelot) surely pertains to the stranger, the fatherless, and the widow, and the mitzvah is accomplished when these classes of people receive the gifts, the small amount of grain involved serves to differentiate these gifts from the tithe that is given to the poor. Thus, it appears that the social reason alone of tzedaqah might be insufficient as an explanation. Moreover, the paradox of shikhah, where one can only perform the mitzvah if one has forgotten to take everything from the field, makes it difficult to understand this mitzvah as exclusively one of tzedakah.

The anonymous Spanish 14th century author of the work known as Sefer Ha-Hinukh adds another reason to the mitzvah of pe’ah (mitzvah #216). His reason pertains to the inculcation of moral qualities in the individual who owns the fields.

The L-RD wished his chosen people to be graced with every good moral quality and that they should be generous in spirit and blessed in soul. I have already written that actions should mold the character, improving it and making it receptive for Divine blessing. There is no doubt that by leaving a portion of his produce and declaring it free to everyone so that the needy may enjoy it, man’s spirit will become more unselfish and he will enjoy divine grace. But he who gathers in everything into the house leaving nothing for the needy who saw the field chock-full of standing corn and had hoped thereby to satiate their hunger, will no doubt do harm to his character, breeding selfishness, ill-will and miserliness…

The same reason suffices to explain the laws of Gleanings, the Forgotten Sheaf, etc.

(Studies in Devarim, p. 245)

The author of the Hinukh adds another point regarding shikhah (Mitzvah #592):

It is commanded because the poor and needy look forward to enjoying some of the produce as they the owner binding the sheaves. They say to themselves: “Would that I be granted to garner in sheaves to my house. If I had only one I would rejoice in the L-rd.”

It was God’s beneficent wish to fulfill their desire, when it happened that the owner forgot a sheaf.

It is also beneficial to the owner of the field by which he acquires a generous nature, since the generous soul does not bother about the sheaf he happens to have forgotten and leaves it to the poor.

Nechama Leibowitz (ad loc.) notes that here the Hinukh adds yet a second additional reason, that the Torah wished to fulfill the desire of the poor to have “at least one” sheaf. She adds the observation from R. Samson Rafael Hirsch, in his commentary to Parashat Ki Tetze: Rav Hirsch adds another dimension which can help explain how the character of the owner of a field is improved by neglecting to go back and recover some grain that he has forgotten.

The gifts to the poor constitute
a contrast, a protest against the concept of “Mine.” The Corner and the Gleanings remind you of your duty not to regard your field and vineyard as your own and exclusively your own, and not to monopolize all that nature with God’s blessing has grown for you. Peret and Leqet remind you that you are not to exploit the labor of your hands exclusively for your own benefit till the very last straw…the Torah adds the precept of the Forgotten Sheaf to teach you that even the thoughts of yours connected with the labor you expend on your possessions must not be exclusively directed for your selfish good, and that includes that which is overlooked by your thoughts during the harvesting. (Studies in Devarim, Hebrew ed., p. 231; English ed., p. 247.)