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.
Judges 16:9
Surrounding context
16:8 So the lords of the Philistines brought up to her seven fresh bowstrings, not yet dried, and she bound him with them.
16:9 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.
16:10 Then Delilah said to Samson, "Look, you have mocked me and told me lies. Now, please tell me what you may be bound with."