Deuteronomy 23:19-23

“You are not to charge interest to your countrymen: interest on money, food, or anything that may be loaned on interest.

You may charge interest to a foreigner, but to your countrymen you shall not charge interest, so that the Lord your God may bless you in all that you undertake in the land which you are about to enter to possess.

“When you make a vow to the Lord your God, you shall not delay to pay it, for the Lord your God will certainly require it of you, and it will be a sin for you.

However, if you refrain from making vows, it will not be a sin for you.

You shall be careful and perform what goes out of your lips, since in fact you have vowed a voluntary offering to the Lord your God, whatever you have promised.