1 Samuel 15:17-19

And Samuel said, “Though you are little in your own eyes, are you not the head of the tribes of Israel? The LORD anointed you king over Israel. And the LORD sent you on a mission and said, ‘Go, devote to destruction the sinners, the Amalekites, and fight against them until they are consumed.’ Why then did you not obey the voice of the LORD? Why did you pounce on the spoil and do what was evil in the sight of the LORD?”