John Calvin Commentary Numbers 24:20

"And he looked on Amalek, and took up his parable, and said, Amalek was the first of the nations; But his latter end shall come to destruction." — Numbers 24:20 (ASV)

And when he looked on Amalek. This people had already been destined for destruction by a Divine decree; but what God had previously declared is here again ratified by Moses. Although the vengeance, which God was about to take, lay dormant for many ages, it was eventually proven by experience that God had not threatened in vain.

But, while it is true that they were destroyed by Saul, we still learn from history that some still survived and again inhabited their land. Therefore, to arrive at the entire accomplishment of this prophecy, we must come to Christ, whose kingdom is the eternal destruction of all the wicked.

Poor and unsatisfactory is the view of some commentators¹⁷⁹ who think that Amalek is called the first of the nations, because they first took up arms against Israel and encountered them to prevent their advance.

Rather is the pride of Amalek indirectly rebuked because they claimed superiority for themselves over other nations, and this on account of their antiquity, as if they had been created together with the sun and moon. There is then a pointed comparison between this noble origin and the slaughter that awaited them at their end.

¹⁷⁹ “So all the paraphrasts,” says Drusius, in Poole’s Syn. See margin A. V., and the gloss in the Geneva Bible. and the gloss in the Geneva Bible.