7 Then Saul slaughtered the Amalekites from Havilah all the way to Shur, east of Egypt. 8 He captured Agag, the Amalekite king, but completely destroyed everyone else. 9 Saul and his men spared Agag's life and kept the best of the sheep and goats, the cattle, the fat calves, and the lambs-everything, in fact, that appealed to them. They destroyed only what was worthless or of poor quality.
Matthew Henry's Commentary on 1 Samuel 15:7-9
Commentary on 1 Samuel 15:1-9
(Read 1 Samuel 15:1-9)
The sentence of condemnation against the Amalekites had gone forth long before, Revelation 18:4. As the commandment had been express, and a test of Saul's obedience, his conduct evidently was the effect of a proud, rebellious spirit. He destroyed only the refuse, that was good for little. That which was now destroyed was sacrificed to the justice of God.