1 Samuel 15:17-19

17Samuel said, “Although you were once small in your own eyes, did you not become the head of the tribes of Israel? The Lord anointed you king over Israel. 18And he sent you on a mission, saying, ‘Go and completely destroy those wicked people, the Amalekites; wage war against them until you have wiped them out.’ 19Why did you not obey the Lord? Why did you pounce on the plunder and do evil in the eyes of the Lord?”