151 And Samuel saith unto Saul, 'Me did Jehovah send to anoint thee for king over His people, over Israel; and now, hearken to the voice of the words of Jehovah: 2 'Thus said Jehovah of Hosts, I have looked after that which Amalek did to Israel, that which he laid for him in the way in his going up out of Egypt. 3 Now, go, and thou hast smitten Amalek, and devoted all that it hath, and thou hast no pity on it, and hast put to death from man unto woman, from infant unto suckling, from ox unto sheep, from camel unto ass.' 4 And Saul summoneth the people, and inspecteth them in Telaim, two hundred thousand footmen, and ten thousand 'are' men of Judah. 5 And Saul cometh in unto a city of Amalek, and layeth wait in a valley; 6 and Saul saith unto the Kenite, 'Go, turn aside, go down from the midst of Amalek, lest I consume thee with it, and thou didst kindness with all the sons of Israel, in their going up out of Egypt;' and the Kenite turneth aside from the midst of Amalek.
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.