10 This very day you can see with your own eyes it isn't true. For the Lord placed you at my mercy back there in the cave. Some of my men told me to kill you, but I spared you. For I said, 'I will never harm the king-he is the Lord 's anointed one.' 11 Look, my father, at what I have in my hand. It is a piece of the hem of your robe! I cut it off, but I didn't kill you. This proves that I am not trying to harm you and that I have not sinned against you, even though you have been hunting for me to kill me. 12 "May the Lord judge between us. Perhaps the Lord will punish you for what you are trying to do to me, but I will never harm you. 13 As that old proverb says, 'From evil people come evil deeds.' So you can be sure I will never harm you.
Matthew Henry's Commentary on 1 Samuel 24:10-13
Commentary on 1 Samuel 24:8-15
(Read 1 Samuel 24:8-15)
David was falsely charged with seeking Saul's hurt; he shows Saul that God's providence had given him opportunity to do it. And it was upon a good principle that he refused to do it. He declares his fixed resolution never to be his own avenger. If men wrong us, God will right us, at farthest, in the judgment of the great day.