1 Samuel 15:7-11

Then Saul defeated the Amalekites, from Havilah going toward Shur, which is east of Egypt.

He captured Agag the king of the Amalekites alive, and completely destroyed all the people with the edge of the sword.

But Saul and the people spared Agag and the best of the sheep, the oxen, the more valuable animals, the lambs, and everything that was good, and were unwilling to destroy them completely; but everything despicable and weak, that they completely destroyed. Samuel Rebukes Saul

Then the word of the Lord came to Samuel, saying,

“I regret that I have made Saul king, because he has turned back from following Me and has not carried out My commands.” And Samuel was furious and cried out to the Lord all night.