Sforno on Leviticus 23:22/ספורנו על ויקרא כ״ג:כ״ב

1ובקצרכם , after giving thanks for the harvest and its successful storing of it in the barns, the Torah warns of what has to be done to ensure that the financial success which this harvest represents not be ruined. This is why the farmer is commanded to set aside, or simply not harvest, such incidentals as are referred to as לקט, שכחה, פאה, which in the words of our sages in Ketuvot 66 are viewed as מלח ממון חסר, ואמרי לה חסד. “money cannot be salted away (for safekeeping.)” Some people, in a play on words, change the word חסר for חסד, loving kindness, a kind of charity,” suggesting that the only way to ensure that one does not lose one’s own money is by engaging liberally in handing out charity to the deserving. The legislation in our verse then is this insurance for the farmer not to lose his crop even after he has already brought it into the barn.

2אני ה' אלוקיכם, the many faceted functions of G’d are alluded to here, i.e. that G’d’s supervision is needed at all stages of the growing of the crop,; He is the G’d of the reapers, the G’d of the collectors. G’d says that “My regulations are designed to be beneficial for you the grower, for the poor who collects the gleanings. I will deal beneficially with those who have already demonstrated their concern for others by complying with the legislation set forth here.”