When you shall vow a vow unto 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.
That which is gone out of your lips you shall keep and perform; even a freewill offering, according as you have vowed unto the LORD your God, which you have promised with your mouth.
And the children of Israel did not strike them, because the princes of the congregation had sworn to them by the LORD God of Israel. And all the congregation murmured against the princes.