As we mentioned in Mitzvah #218, this phrase, “you shall leave them for the poor…” refers to a whole bunch of things that the Torah tells us not to take. Here’s another one.
The part of the vineyard to be left for the poor is called olelos. We’ll discuss exactly what constitutes olelos in the next mitzvah. The reason to leave olelos in a vineyard is the same as to leave the corner (peah) and gleanings (leket) in a field: God wants us to share what He has given us. By doing so, we cultivate our traits of compassion and generosity.
This mitzvah applies to everyone but only in Israel. It is discussed in the seventh chapter of tractate Peah in the Mishnah and is codified in the Shulchan Aruch in Yoreh De’ah 332. It is #123 of the 248 positive mitzvos in the Rambam’s Sefer HaMitzvos and #3 of the 26 mitzvos that can only be performed in Israel according to the Steipler Gaon.