I Samuel 15:13-15

Then Samuel went to Saul, and Saul said to him, “Blessed are you of the LORD! I have performed the commandment of the LORD.” But Samuel said, “What then is this bleating of the sheep in my ears, and the lowing of the oxen which I hear?” And Saul said, “They have brought them from the Amalekites; for the people spared the best of the sheep and the oxen, to sacrifice to the LORD your God; and the rest we have utterly destroyed.”