1 Samuel 26:6-9

6David said to Ahimelech the Hittite and Abishai son of Zeruiah, Joab’s brother, “Who will go down with me to Saul in the camp?” Abishai replied, “I will go down with you.”

7So David and Abishai approached the army at night and found Saul lying asleep in the entrenchment with his spear stuck in the ground by his head. Abner and the army were lying all around him.

8Abishai said to David, “Today God has delivered your enemy into your hands. Now let me drive the spear right through him into the ground with one swift jab! A second jab won’t be necessary!”

9But David said to Abishai, “Don’t kill him! Who can extend his hand against the Lord’s chosen one and remain guiltless?”