Deuteronomy 24:18-22

18Remember that you were a slave in Egypt, and the Lord your God redeemed you from there. Therefore I am commanding you to do this.

19“When you reap the harvest in your field, and you forget a sheaf in the field, do not go back to get it. It is to be left for the resident alien, the fatherless, and the widow, so that the Lord your God may bless you in all the work of your hands.

20When you knock down the fruit from your olive tree, do not go over the branches again. What remains will be for the resident alien, the fatherless, and the widow.

21When you gather the grapes of your vineyard, do not glean what is left. What remains will be for the resident alien, the fatherless, and the widow.

22Remember that you were a slave in the land of Egypt. Therefore I am commanding you to do this.