the first: i.e. the first that warred against Israel. Exodus 17:8. Not the first in time or importance. shall be, &c.. "[shall be] destruction". Compare Exodus 17:16.
Related Commentaries of Numbers 24:20
Numbers 24:20
20 And when he looked on Amalek, he took up his parable, and said, Amalek was the first of the nations;c but his latter end shall be that he perish for ever.