Deuteronomy 23:20-22

Revised Standard Version Catholic Edition

²⁰ To a foreigner you may lend upon interest, but to your brother you shall not lend upon interest; that the Lord your God may bless you in all that you undertake in the land which you are entering to take possession of it.

²¹ “When you make a vow to the Lord your God, you shall not be slack to pay it; for the Lord your God will surely require it of you, and it would be sin in you. ²² But if you refrain from vowing, it shall be no sin in you.