1 Samuel 15

God commands Saul through Samuel to utterly destroy the wicked Amalekites—men, women, children, and livestock—as judgment for their attack on Israel during the Exodus. Saul defeats the Amalekites but disobediently spares King Agag and the best of the livestock, claiming the animals are for sacrifice. Samuel confronts Saul for his incomplete obedience, delivering the famous declaration: "To obey is better than sacrifice." Samuel then brutally executes King Agag, and God tells Samuel that He regrets making Saul king over Israel due to his disobedience.