1 Samuel 15:9-11

Saul and the army let Agag live, along with the best sheep, fat cattle, and lambs. They let every good animal live, because they did not want to destroy them. But when they found an animal that was weak or useless, they killed it. Then the LORD spoke his word to Samuel: “I am sorry I made Saul king, because he has stopped following me and has not obeyed my commands.” Samuel was upset, and he cried out to the LORD all night long.