'Vow' in the Bible

Don't bring the earnings of a female prostitute nor the income of a male prostitute into the house of the LORD your God as payment for any vow. Both of these are detestable to the LORD your God."

"When you make a vow to the LORD your God, don't delay paying it, because the LORD your God will certainly demand payment from you, and then you will be guilty of sin.

But if you refrain from making a vow, then you won't be guilty.