'Vowing' in the Bible

'And if he is poorer than thy valuation, then he hath presented himself before the priest, and the priest hath valued him; according to that which the hand of him who is vowing doth reach doth the priest value him.

'Speak unto the sons of Israel, and thou hast said unto them, When a man or woman doeth singularly, by vowing a vow of a Nazarite, to be separate to Jehovah;

However, if you refrain from vowing, it would not be sin in you.

how he swore an oath to the LORD, vowing to the Mighty One of Jacob,

And cursed is a deceiver, who hath in his drove a male, And is vowing, and is sacrificing a marred thing to the Lord, For a great king am I, said Jehovah of Hosts, And My name is revered among nations!