Judges 16:9

Now she had an ambush waiting in the inner room. She said to him, “The Philistines are on you, Samson!” He broke the cords as a flax thread is broken when it touches the fire. So his strength was not known.

Now there were men lying in wait, abiding with her in the chamber. And she said unto him, The Philistines be upon thee, Samson. And he brake the withs, as a thread of tow is broken when it toucheth the fire. So his strength was not known.