1 Samuel 15:29-33

And also the Strength of Israel will not lie nor repent: for he is not a man, that he should repent.

Then he said, I have sinned: yet honour me now, I pray thee, before the elders of my people, and before Israel, and turn again with me, that I may worship the LORD thy God.

So Samuel turned again after Saul; and Saul worshipped the LORD.

Then said Samuel, Bring ye hither to me Agag the king of the Amalekites. And Agag came unto him delicately. And Agag said, Surely the bitterness of death is past.

And Samuel said, As thy sword hath made women childless, so shall thy mother be childless among women. And Samuel hewed Agag in pieces before the LORD in Gilgal.