1 Samuel 15:9-11

15:9 However, Saul and the army spared Agag, along with the best of the flock, the cattle, the fatlings, and the lambs, as well as everything else that was of value. They were not willing to slaughter them. But they did slaughter everything that was despised and worthless.

15:10 Then the word of the Lord came to Samuel: 15:11 “I regret that I have made Saul king, for he has turned away from me and has not done what I told him to do.” Samuel became angry and he cried out to the Lord all that night.