Judges 16:17-19
16:17 Finally he told her his secret. He said to her, “My hair has never been cut, for I have been dedicated to God from the time I was conceived. If my head were shaved, my strength would leave me; I would become weak, and be just like all other men.”
16:18 When Delilah saw that he had told her his secret, she sent for the rulers of the Philistines, saying, “Come up here again, for he has told me his secret.” So the rulers of the Philistines went up to visit her, bringing the silver in their hands.
16:19 She made him go to sleep on her lap and then called a man in to shave off the seven braids of his hair. She made him vulnerable and his strength left him.