21. When you vow a vow to Yahweh your God, you shall not be slack to pay it; for Yahweh your God will surely require it of you; and it would be sin in you.
22. But if you refrain from making a vow, it shall be no sin in you.
23. You shall observe and do that which has gone out of your lips. Whatever you have vowed to Yahweh your God as a freewill offering, which you have promised with your mouth, you must do.