3,124. The Minimum Volume of Peah

Hilchos Matnos Aniyim 1:14

Under Biblical law, all of the gifts for the needy are only required in Israel, the same as t’rumah and tithes. This is derived from Leviticus 19:9 – "When you reap the harvest of your land" – and Deuteronomy 24:19 – "When you reap your harvest in your field." The Gemara explains that peah is obligatory outside of Israel under rabbinic law; the Rambam opines that this law logically applies to all the other gifts for the needy. The result is that all of these mitzvos are observed outside of Israel under rabbinic law.

Hilchos Matnos Aniyim 1:15

Under Biblical law, there is no minimum requirement for peah; leaving even a single stalk fulfills one’s obligation. However, under rabbinic law a person must leave 1/60 of his crop, both in Israel and elsewhere. One should add to this 1/60 according to the size of his field, the number of needy seeking aid, and the output of his crop. Accordingly, if a field is so small that 1/60 of it wouldn’t do much good for the needy, the owner should increase the size of his peah. The same is true if there are many needy people. If the owner planted a little and harvested a lot, he has been blessed and he should increase his peah to reflect this blessing. Whoever increases his peah will be amply rewarded. There’s no upper limit to how much peah one can leave.