1 Samuel 19:4-5

4Jonathan 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.

5He 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?”