1Sam 26:6-9

6Then David said to Ahimelech the Hittite, and to Joab's brother Abishai son of Zeruiah, “Who will go down with me into the camp to Saul?” Abishai said, “I will go down with you.”7So David and Abishai went to the army by night; there Saul lay sleeping within the encampment, with his spear stuck in the ground at his head; and Abner and the army lay around him.8Abishai said to David, “God has given your enemy into your hand today; now therefore let me pin him to the ground with one stroke of the spear; I will not strike him twice.”9But David said to Abishai, “Do not destroy him; for who can raise his hand against the Lord's anointed, and be guiltless?”