1 Samuel 15:2-9

Thus says the LORD of hosts, ‘I have noted what Amalek did to Israel in opposing them on the way when they came up out of Egypt. Now go and strike Amalek and devote to destruction all that they have. Do not spare them, but kill both man and woman, child and infant, ox and sheep, camel and donkey.’” So Saul summoned the people and numbered them in Telaim, two hundred thousand men on foot, and ten thousand men of Judah. And Saul came to the city of Amalek and lay in wait in the valley. Then Saul said to the Kenites, “Go, depart; go down from among the Amalekites, lest I destroy you with them. For you showed kindness to all the people of Israel when they came up out of Egypt.” So the Kenites departed from among the Amalekites. And Saul defeated the Amalekites from Havilah as far as Shur, which is east of Egypt. And he took Agag the king of the Amalekites alive and devoted to destruction all the people with the edge of the sword. But Saul and the people spared Agag and the best of the sheep and of the oxen and of the fattened calves and the lambs, and all that was good, and would not utterly destroy them. All that was despised and worthless they devoted to destruction.