An evil spirit from Yahweh was on Saul, as he sat in his house with his spear in his hand; and David was playing with his hand.
and David played with [his] hand; on some instrument of music, particularly the harp, to drive away the evil spirit, the melancholy disorder, from Saul; which showed his humility, that though he was an officer in the army, had a considerable post in it, yet deigned to act the part of a musician to Saul, and his great kindness and affection for him his sovereign, willing to serve him what he could to promote his health and comfort, and the trust and confidence he put in his promise and oath, or rather in the providence of God for his protection in the way of his duty, though he knew how spiteful and injurious Saul had been to him.