The 210th prohibition is that we are forbidden from completely harvesting a field. Rather, we must leave over a portion of the end of the field for the poor.

The source of this commandment is G‑d's statement,1 "Do not completely harvest the ends of your fields."

This prohibition is a lav shenitak l'aseh (a prohibition with a remedial positive commandment). Therefore, if one violated this law and harvested the entire field, he must give the poor enough of the harvested food to match what he should have left over to begin with. This positive commandment is contained in the verse, "Leave them for the poor and the stranger," as we previously explained.2

One must leave over the corner of a tree just like the corner of a field.

The Biblical prohibition applies only in Eretz Yisroel.3

The details of this mitzvah are found in the tractate devoted to this subject [i.e., Pe'ah].