1 Samuel 15:17-19

17Samuel said, “Is it not true that when you were insignificant in your own eyes, you became head of the tribes of Israel? The Lord chose you as king over Israel.

18The Lord sent you on a campaign saying, ‘Go and exterminate those sinful Amalekites! Fight against them until you have destroyed them.’

19Why haven’t you obeyed the Lord? Instead you have greedily rushed upon the plunder! You have done what is wrong in the Lord’s estimation.”