1 Samuel 15:13-15

So Samuel came to Saul, and Saul said to him, “Blessed are you of the LORD. I have carried out the command 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?” Saul said, “They have brought them from the Amalekites, for the people spared the best of the sheep and oxen to sacrifice to the LORD your God; but the rest we have destroyed completely.”