1st Samuel 26:7

4 And so David sent out watchers, and got word from them that Saul was certainly coming.

5 And David got up and came to the place where Saul's tents were: and David had a view of the place where Saul was sleeping with Abner, the son of Ner, the captain of his army: and Saul was sleeping inside the ring of carts, and the tents of the people were all round him.

6 Then David said to Ahimelech the Hittite, and to Abishai, the son of Zeruiah, brother of Joab, Who will go down with me to the tents of Saul? And Abishai said, I will go down with you.

7 So David and Abishai came down to the army by night: and Saul was sleeping inside the ring of carts with his spear planted in the earth by his head: and Abner and the people were sleeping round him.

8 Then Abishai said to David, God has given up your hater into your hands today; now let me give him one blow through to the earth with his spear, and there will be no need to give him a second.

9 And David said to Abishai Do not put him to death; for who, without sin, may put out his hand against the man on whom the Lord has put the holy oil?

10 And David said, By the living Lord, the Lord will send destruction on him; the natural day of his death will come, or he will go into the fight and come to his end.