Nahum 1:12 - Matthew Poole's English Annotations on the Holy Bible

Thus saith the Lord: this addeth weight to his prediction, it comes under the great seal of Heaven. Though they be quiet, and likewise many; or, If they would have been quiet and peaceable towards my people, Israel, they, i.e. the Assyrians, should have been many, &c.; but I think it is nearer to the intent of the place to retain our version. Though they, citizens of Nineveh, and people of Assyria, be quiet, be secure, and fear no danger, because of their strength and victories, and likewise many; as appears by the mighty army with which they besieged Jerusalem, in which one hundred and eighty-five thousand were cut off in one night. Yet thus, irresistibly, suddenly, and universally, as is foretold Nahum 1:10, shall they be cut down: the prophet varieth his phrase, for, Nahum 1:10, he speaks of it as done by fire, here he speaks of cutting down, intimating that it was the sword which should cut them off. When he shall pass through; either God, the mighty and terrible One, passing over as a flood, as it is Nahum 1:8; or else the angel of the Lord, as 2 Kings 19:35. Though I, the Lord, who am good to my people, have afflicted thee, O Israel, I will afflict thee no more; chastised by the Assyrian, the rod of mine anger, hast thou been, O my people, but I will no more use that rod; for they should soon cease to be a nation that ruleth, and be conquered and oppressed by others.