1 Samuel 18:5-9

 ⁵ Whatever Saul sent him to do, David did it so successfully that Saul gave him a high rank in the army. This pleased all the people, and Saul's officers as well.

 ⁶ When the men were returning home after David had killed the Philistine, the women came out from all the towns of Israel to meet King Saul with singing and dancing, with joyful songs and with tambourines and lutes. ⁷ As they danced, they sang: 
       "Saul has slain his thousands, and David his tens of thousands."

 ⁸ Saul was very angry; this refrain galled him. "They have credited David with tens of thousands," he thought, "but me with only thousands. What more can he get but the kingdom?" ⁹ And from that time on Saul kept a jealous eye on David.