1 Samuel 26:3-5
3-5David, still out in the backcountry, knew Saul had come after him. He sent scouts to determine his precise location. Then David set out and came to the place where Saul had set up camp and saw for himself where Saul and Abner, son of Ner, his general, were staying. Saul was safely inside the camp, encircled by the army.
6Taking charge, David spoke to Ahimelech the Hittite and to Abishai son of Zeruiah, Joab's brother: "Who will go down with me and enter Saul's camp?"
Abishai whispered, "I'll go with you."