Judges 16:9
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.
Cross-references
Judges 16:20
Contrast
Judges 16:20 shows Samson's later failure when the Lord departed — contrasting with his success here.
Judges 15:14
Parallel
Judges 15:14 records a similar breaking of bonds by Samson's supernatural strength — here again he snaps bowstrings.