1 Samuel 15:8

4 So Saul summoned the troops and numbered them at Telaim—200,000 foot soldiers and 10,000 men of Judah.

5 Saul came to the city of Amalek and lay in wait in the valley.

6 And he warned the Kenites, “Since you showed kindness to all the Israelites when they came up out of Egypt, go on and get away from the Amalekites. Otherwise I will sweep you away with them.” So the Kenites moved away from the Amalekites.

7 Then Saul struck down the Amalekites all the way from Havilah to Shur, which is east of Egypt.

8 He captured Agag king of Amalek alive, but devoted all the others to destruction with the sword.

9 Saul and his troops spared Agag, along with the best of the sheep and cattle, the fat calves and lambs, and the best of everything else. They were unwilling to destroy them, but they devoted to destruction all that was despised and worthless.

10 Then the word of the LORD came to Samuel, saying,

11 “I regret that I have made Saul king, for he has turned away from following Me and has not carried out My instructions.” And Samuel was distressed and cried out to the LORD all that night.

12 Early in the morning Samuel got up to confront Saul, but he was told, “Saul has gone to Carmel, and behold, he has set up a monument for himself and has turned and gone down to Gilgal.”

Read all of 1 Samuel 15