1 Samuel 26:7-14, 21-25

So David and Abishai came to the people by night: and, behold, Saul lay sleeping within the trench, and his spear stuck in the ground at his bolster: but Abner and the people lay round about him. Then said Abishai to David, God hath delivered thine enemy into thine hand this day: now therefore let me smite him, I pray thee, with the spear even to the earth at once, and I will not smite him the second time. And David said to Abishai, Destroy him not: for who can stretch forth his hand against the LORD's anointed, and be guiltless? David said furthermore, As the LORD liveth, the LORD shall smite him; or his day shall come to die; or he shall descend into battle, and perish. The LORD forbid that I should stretch forth mine hand against the LORD's anointed: but, I pray thee, take thou now the spear that is at his bolster, and the cruse of water, and let us go. So David took the spear and the cruse of water from Saul's bolster; and they gat them away, and no man saw it, nor knew it, neither awaked: for they were all asleep; because a deep sleep from the LORD was fallen upon them. Then David went over to the other side, and stood on the top of an hill afar off; a great space being between them: and David cried to the people, and to Abner the son of Ner, saying, Answerest thou not, Abner? Then Abner answered and said, Who art thou that criest to the king?

Then said Saul, I have sinned: return, my son David: for I will no more do thee harm, because my soul was precious in thine eyes this day: behold, I have played the fool, and have erred exceedingly. And David answered and said, Behold the king's spear! and let one of the young men come over and fetch it. The LORD render to every man his righteousness and his faithfulness: for the LORD delivered thee into my hand to day, but I would not stretch forth mine hand against the LORD's anointed. And, behold, as thy life was much set by this day in mine eyes, so let my life be much set by in the eyes of the LORD, and let him deliver me out of all tribulation. Then Saul said to David, Blessed be thou, my son David: thou shalt both do great things, and also shalt still prevail. So David went on his way, and Saul returned to his place.