1 Samuel 24:2-5

2Then Saul took three thousand chosen men from all Israel, and went to seek David and his men on the Rocks of the Wild Goats.

3So he came to the sheepfolds by the road, where there was a cave; and Saul went in to attend to his needs. (David and his men were staying in the recesses of the cave.)

4Then the men of David said to him, “This is the day of which the Lord said to you, ‘Behold, I will deliver your enemy into your hand, that you may do to him as it seems good to you.’ ” And David arose and secretly cut off a corner of Saul’s robe.

5Now it happened afterward that David’s heart troubled him because he had cut Saul’s robe.