Flavius Josephus, Antiquities of the Jews
William Whiston, A.M., Ed.

[131] NOW Samuel came unto Saul, and said to him, that he was sent by God to put him in mind that God had preferred him before all others, and ordained him king; that he therefore ought to be obedient to him, and to submit to his authority, as considering, that though he had the dominion over the other tribes, yet that God had the dominion over him, and over all things. That accordingly God said to him, that "because the Amalekites did the Hebrews a great deal of mischief while they were in the wilderness, and when, upon their coming out of Egypt, they were making their way to that country which is now their own, I enjoin thee to punish the Amalekites, by making war upon them; and when thou hast subdued them, to leave none of them alive, but to pursue them through every age, and to slay them, beginning with the women and the infants, and to require this as a punishment to be inflicted upon them for the mischief they did to our forefathers; to spare nothing, neither asses nor other beasts, nor to reserve any of them for your own advantage and possession, but to devote them universally to God, and, in obedience to the commands of Moses, to blot out the name of Amalek entirely." ¹