Albert Barnes Commentary Isaiah 17:12

"Ah, the uproar of many peoples, that roar like the roaring of the seas; and the rushing of nations, that rush like the rushing of mighty waters!" — Isaiah 17:12 (ASV)

Wo to the multitude ... - The word ‘woe’ (הוי hôy) may be either an interjection simply directing the attention to them, or it may be a word indicating approaching calamity and judgment (see the note at Isaiah 5:6). Gesenius supposes that it is rather the language of compassion, on account of the evil which they threatened to bring upon the people of God, like 1 Kings 13:30, ‘Ah! wo, my brother!’

The multitude of many people - Or, the tumult of many nations – a description of the noise attending an invading army made up of many nations mingled together, like that of Sennacherib.

Which make a noise ... - This is a beautiful description of a vast army, and of the shouting, the tumult, the din, which attends its march. The same comparison occurs in Jeremiah 6:23; Psalms 65:7 (Revelation 1:15; Revelation 14:2; Revelation 19:6).

And to the rushing of nations - The rushing of mighty armies to conquest.