1 Samuel 19:1-6
19:1 Saul told his son Jonathan and all the attendants to kill David. But Jonathan had taken a great liking to David 2 and warned him, “My father Saul is looking for a chance to kill you. Be on your guard tomorrow morning; go into hiding and stay there. 3 I will go out and stand with my father in the field where you are. I’ll speakto him about you and will tell you what I find out.”
4 Jonathan spoke well of David to Saul his father and said to him, “Let not the king do wrong to his servant David; he has not wronged you, and what he has done has benefited you greatly. 5 He took his life in his hands when he killed the Philistine. The Lord won a great victory for all Israel, and you saw it and were glad. Why then would you do wrong to an innocent man like David by killing him for no reason?”
6 Saul listened to Jonathan and took this oath: “As surely as the Lord lives, David will not be put to death.”