1 Samuel 16:19-23

19Therefore Saul sent messengers to Jesse and said, "Send me David your son, who is with the sheep."

20And Jesse took a donkey laden with bread and a skin of wine and a young goat and sent them by David his son to Saul.

21And David came to Saul and entered his service. And Saul loved him greatly, and he became his armor-bearer.

22And Saul sent to Jesse, saying, "Let David remain in my service, for he has found favor in my sight."

23And whenever the harmful spirit from God was upon Saul, David took the lyre and played it with his hand. So Saul was refreshed and was well, and the harmful spirit departed from him.