Deuteronomy 23:19-21

Modern English Version

¹⁹ You must not charge interest on a loan to your brother: interest on money, interest on food, or on anything that may be lent with interest. ²⁰ You may charge interest to a foreigner, but to your brother you may not lend with interest so that the Lord your God may bless you in all to which you set your hand in the land which you are entering to possess.

²¹ When you make a vow to the Lord your God, you must not be slow to pay it, for the Lord your God will surely require it of you, and it would be a sin to you.