1 Samuel 26:3-7

And Saul camped on the hill of Hachilah, which is opposite Jeshimon, beside the road, and David was staying in the wilderness. When he saw that Saul had come after him into the wilderness,

David sent out spies, and he learned that Saul was definitely coming.

David then set out and came to the place where Saul had camped. And David saw the place where Saul lay, and Abner the son of Ner, the commander of his army; and Saul was lying in the circle of the camp, and the people were camped around him.

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

So David and Abishai came to the people by night, and behold, Saul lay sleeping inside the circle of the camp with his spear stuck in the ground at his head; and Abner and the people were lying around him.