1 Samuel 18:5-16
And David went out and was successful wherever Saul sent him; so that Saul set him over the men of war. And this was good in the sight of all the people and also in the sight of Saul's servants. As they were coming home, when David returned from slaying the Philistine, the women came out of all the cities of Israel, singing and dancing, to meet King Saul, with timbrels, with songs of joy, and with instruments of music. And the women sang to one another as they made merry, "Saul has slain his thousands, and David his ten thousands."
And Saul was very angry, and this saying displeased him; he said, "They have ascribed to David ten thousands, and to me they have ascribed thousands; and what more can he have but the kingdom?" And Saul eyed David from that day on. And on the morrow an evil spirit from God rushed upon Saul, and he raved within his house, while David was playing the lyre, as he did day by day. Saul had his spear in his hand; and Saul cast the spear, for he thought, "I will pin David to the wall." But David evaded him twice.
Saul was afraid of David, because the LORD was with him but had departed from Saul. So Saul removed him from his presence, and made him a commander of a thousand; and he went out and came in before the people. And David had success in all his undertakings; for the LORD was with him. And when Saul saw that he had great success, he stood in awe of him. But all Israel and Judah loved David; for he went out and came in before them.