So Delilah said to Samson, "Please tell me the source of your great strength and how you can be tied up and subdued."

Judges 16:5
The lords of the Philistines went to her and said, "Entice him and find out the source of his great strength and how we can overpower him to tie him up and subdue him. Then each one of us will give you eleven hundred shekels of silver."

Judges 16:7
Samson told her, "If they tie me up with seven fresh bowstrings that have not been dried, I will become as weak as any other man."

And Delilah said to Samson, Tell me, I pray you, wherein your great strength lies, and with which you might be bound to afflict you.