Deuteronomy 24:17-19

17Remember to be completely fair to foreigners and to children who have no family. If you lend money to a widow, do not take her coat as a guarantee.

18Remember that you were slaves in Egypt and the Lord your God rescued you from there. That is why I am commanding you to do these things.

19At harvest time, you might forget to bring in all the crops from your fields. Do not go back to pick up all the grain. Leave it there for foreigners, widows and children who have no family. If you do that, the Lord your God will bless you in all your work.