Deuteronomy 24:14-15

14Do not be cruel to any poor or helpless person who works for you. Be kind to him, whether he is an Israelite or a foreigner who lives in one of your towns.

15You must pay him for his work every day before sunset. Remember that he is poor. He needs the money to stay alive. If you do not pay him, he may complain against you to the Lord. The Lord would say that you are guilty of a sin.