John Gill Commentary Judges 16:10

"And Delilah said unto Samson, Behold, thou hast mocked me, and told me lies: now tell me, I pray thee, wherewith thou mightest be bound." — Judges 16:10 (ASV)

And Delilah said to Samson
Not on the same day, but some time after, as Kimchi observes, when an opportunity offered, and he was in like circumstances as before; for had she immediately attacked him, it might have created some suspicion in him of a design against him:

behold, you have mocked me, and told me lies ;
deceived her with lies, by telling her the other day that if he was bound with green withs, he should become as weak as other men; which she, out of curiosity as she might pretend, had tried, and had found to be false; and which, she might add, was an argument of want of true love to her, to mock her in such a manner:

now tell me, I pray you, with what you might be bound ;
so as to be held.