1 Samuel 15:17-19

17And Samuel said, “Although you were once small in your own eyes, have you not become the head of the tribes of Israel? The LORD anointed you king over Israel 18and sent you on a mission, saying, ‘Go and devote to destruction the sinful Amalekites. Fight against them until you have wiped them out.’ 19So why did you not obey the LORD? Why did you rush upon the plunder and do evil in the sight of the LORD?”