Judges 16:15-17 NIV

[15] Then she said to him, “How can you say, ‘I love you,’ when you won’t confide in me? This is the third time you have made a fool of me and haven’t told me the secret of your great strength.” [16] With such nagging she prodded him day after day until he was sick to death of it. [17] 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.”