Deuteronomy 23:22

20You may charge a foreigner interest; but you shall not charge your brother interest, that the LORD your God may bless you in all that you put your hand to, in the land where you go in to possess it.

21When you vow 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.

22But if you refrain from making a vow, it shall be no sin in you.

23You shall observe and do that which has gone out of your lips. Whatever you have vowed to the LORD your God as a free will offering, which you have promised with your mouth, you must do.

24When you come into your neighbor’s vineyard, then you may eat your fill of grapes at your own pleasure; but you shall not put any in your container.