I Samuel 15:6-13

Then Saul said to the Kenites, “Go, depart, get down from among the Amalekites, lest I destroy you with them. For you showed kindness to all the children of Israel when they came up out of Egypt.” So the Kenites departed from among the Amalekites. And Saul attacked the Amalekites, from Havilah all the way to Shur, which is east of Egypt. He also took Agag king of the Amalekites alive, and utterly 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 fatlings, the lambs, and all that was good, and were unwilling to utterly destroy them. But everything despised and worthless, that they utterly destroyed. Now the word of the LORD came to Samuel, saying, “I greatly regret that I have set up Saul as king, for he has turned back from following Me, and has not performed My commandments.” And it grieved Samuel, and he cried out to the LORD all night. So when Samuel rose early in the morning to meet Saul, it was told Samuel, saying, “Saul went to Carmel, and indeed, he set up a monument for himself; and he has gone on around, passed by, and gone down to Gilgal.” Then Samuel went to Saul, and Saul said to him, “Blessed are you of the LORD! I have performed the commandment of the LORD.”