Deuteronomy 24:17-19

17Do not deny justice to a resident alien or fatherless child, and do not take a widow’s garment as security.

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.