Judges 16:17-19

So he told her everything. “No razor has ever been used on my head,” he said, “because I have been a Nazirite dedicated to God from my mother’s womb. If my head were shaved, my strength would leave me, and I would become as weak as any other man.” When Delilah saw that he had told her everything, she sent word to the rulers of the Philistines, “Come back once more; he has told me everything.” So the rulers of the Philistines returned with the silver in their hands. After putting him to sleep on her lap, she called for someone to shave off the seven braids of his hair, and so began to subdue him. And his strength left him.