151 And Samuel said to Saul, The Lord sent me to put the holy oil on you and to make you king over his people, over Israel: so give ear now to the words of the Lord. 2 The Lord of armies says, I will give punishment to Amalek for what he did to Israel, fighting against him on the way when Israel came out of Egypt. 3 Go now and put Amalek to the sword, putting to the curse all they have, without mercy: put to death every man and woman, every child and baby at the breast, every ox and sheep, camel and ass. 4 And Saul sent for the people and had them numbered in Telaim, two hundred thousand footmen and ten thousand men of Judah. 5 And Saul came to the town of Amalek, and took up his position in the valley secretly. 6 And Saul said to the Kenites, Go away, take yourselves out from among the Amalekites, or destruction will overtake you with them: for you were kind to the children of Israel when they came out of Egypt. So the Kenites went away from among the Amalekites.
Matthew Henry's Commentary on 1 Samuel 15:1-6
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.