Judges 16:6-9

So Delilah said to Samson, “Please tell me where your great strength lies, and with what you may be bound to afflict you.” And Samson said to her, “If they bind me with seven fresh bowstrings, not yet dried, then I shall become weak, and be like any other man.” So the lords of the Philistines brought up to her seven fresh bowstrings, not yet dried, and she bound him with them. Now men were lying in wait, staying with her in the room. And she said to him, “The Philistines are upon you, Samson!” But he broke the bowstrings as a strand of yarn breaks when it touches fire. So the secret of his strength was not known.