Then the lords of the Philistines brought up to her seven green cords which had not been dried, and she bound him with them.
The reason Samson lost his strength was only secondarily that he allowed Delilah to cut his hair. The real reason was that "the Lord had departed from him" (Judges 16:20). When God’s Spirit departed from someone under the Old Covenant, the results were disastrous (cf. 1 Samuel 16:14; Psalms 51:11).