Deuteronomy 23:20-22

Amplified Bible, Classic Edition

²⁰ You may lend on interest to a foreigner, but to your brother you shall not lend on interest, that the Lord your God may bless you in all that you undertake in the land to which you go to possess it.

²¹ When you make a vow to the Lord your God, you shall not be slack in paying it, for the Lord your God will surely require it of you, and slackness would be sin in you.

²² But if you refrain from vowing, it will not be sin in you.