1 Samuel 15:10

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.”