1 Samuel 26:4-14

4 David sent out spies, and learned that Saul had indeed arrived.
5 Then David set out and came to the place where Saul had encamped; and David saw the place where Saul lay, with Abner son of Ner, the commander of his army. Saul was lying within the encampment, while the army was encamped around him.
6 Then 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."
7 So 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.
8 Abishai 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."
9 But David said to Abishai, "Do not destroy him; for who can raise his hand against the Lord's anointed, and be guiltless?"
10 David said, "As the Lord lives, the Lord will strike him down; or his day will come to die; or he will go down into battle and perish.
11 The Lord forbid that I should raise my hand against the Lord's anointed; but now take the spear that is at his head, and the water jar, and let us go."
12 So David took the spear that was at Saul's head and the water jar, and they went away. No one saw it, or knew it, nor did anyone awake; for they were all asleep, because a deep sleep from the Lord had fallen upon them.
13 Then David went over to the other side, and stood on top of a hill far away, with a great distance between them.
14 David called to the army and to Abner son of Ner, saying, "Abner! Will you not answer?" Then Abner replied, "Who are you that calls to the king?"
New Revised Standard Version Bible, copyright 1989, Division of Christian Education of the National Council of the Churches of Christ in the United States of America. Used by permission. All rights reserved.