Deuteronomy 24:18-22

Always remember that you were slaves in Egypt and that the LORD your God redeemed you from your slavery. That is why I have given you this command. “When you are harvesting your crops and forget to bring in a bundle of grain from your field, don’t go back to get it. Leave it for the foreigners, orphans, and widows. Then the LORD your God will bless you in all you do. When you beat the olives from your olive trees, don’t go over the boughs twice. Leave the remaining olives for the foreigners, orphans, and widows. When you gather the grapes in your vineyard, don’t glean the vines after they are picked. Leave the remaining grapes for the foreigners, orphans, and widows. Remember that you were slaves in the land of Egypt. That is why I am giving you this command.