Numbers 6:2

“Speak to the sons of Israel and say to them, ‘When a man makes a difficult vow, he shall be valued according to your valuation of persons belonging to Yahweh.

“So now, be careful not to drink wine or strong drink, nor eat any unclean thing.

“For behold, you shall be with child and give birth to a son, and no razor shall come upon his head, for the boy shall be a Nazirite to God from the womb; and he shall begin to save Israel from the hand of the Philistines.”

So he told her all that was in his heart and said to her, “A razor has never come on my head, for I have been a Nazirite to God from my mother’s womb. If I am shaved, then my strength will leave me and I will become weak and be like every other man.”

But they said, “We will not drink wine, for Jonadab the son of Rechab, our father, commanded us, saying, ‘You shall not drink wine, you or your sons, forever.

“Then I raised up some of your sons to be prophets And some of your choice men to be Nazirites. Is this not so, O sons of Israel?” declares Yahweh.

And Paul, having remained many days longer, took leave of the brothers and put out to sea for Syria, and with him were Priscilla and Aquila. In Cenchreae he had his hair cut, for he was keeping a vow.