Deuteronomy 24:20-22

When you beat your olive tree, you shall not go over the boughs again; it shall be for the alien, for the orphan, and for the widow. “When you gather the grapes of your vineyard, you shall not go over it again; it shall be for the alien, for the orphan, and for the widow. You shall remember that you were a slave in the land of Egypt; therefore I am commanding you to do this thing.