1 Samuel 15:1-11

1 Samuel said to Saul, "The Lord sent me to anoint you king over his people Israel; now therefore listen to the words of the Lord.
2 Thus says the Lord of hosts, "I will punish the Amalekites for what they did in opposing the Israelites when they came up out of Egypt.
3 Now go and attack Amalek, and utterly destroy all that they have; do not spare them, but kill both man and woman, child and infant, ox and sheep, camel and donkey.' "
4 So Saul summoned the people, and numbered them in Telaim, two hundred thousand foot soldiers, and ten thousand soldiers of Judah.
5 Saul came to the city of the Amalekites and lay in wait in the valley.
6 Saul said to the Kenites, "Go! Leave! Withdraw from among the Amalekites, or I will destroy you with them; for you showed kindness to all the people of Israel when they came up out of Egypt." So the Kenites withdrew from the Amalekites.
7 Saul defeated the Amalekites, from Havilah as far as Shur, which is east of Egypt.
8 He took King Agag of the Amalekites alive, but utterly destroyed all the people with the edge of the sword.
9 Saul and the people spared Agag, and the best of the sheep and of the cattle and of the fatlings, and the lambs, and all that was valuable, and would not utterly destroy them; all that was despised and worthless they utterly destroyed.
10 The word of the Lord came to Samuel:
11 "I regret that I made Saul king, for he has turned back from following me, and has not carried out my commands." Samuel was angry; and he cried out to the Lord all night.