1 Samuel 16:21-25

Then David came to Saul and attended him; and Saul greatly loved him, and he became his armor bearer.

So Saul sent word to Jesse, saying, “Let David now be my attendant for he has found favor in my sight.”

So it came about whenever the evil spirit from God came to Saul, David would take the harp and play it with his hand; and Saul would feel relieved and become well, and the evil spirit would leave him.