1 Samuel 26:5-7

5And David arose and came to the place where Saul had encamped; and David beheld the place where Saul lay, and Abner the son of Ner, the captain of his host; and Saul lay within the wagon-defence, and the people were encamped round about him.

6And David spake and said to Ahimelech the Hittite, and to Abishai the son of Zeruiah, Joab's brother, saying, Who will go down with me to Saul to the camp? And Abishai said, I will go down with thee.

7And David and Abishai came to the people by night, and behold, Saul lay sleeping within the wagon-defence, and his spear stuck in the ground at his head; and Abner and the people lay round about him.