Matthew Poole's Concise Commentary
Isaiah 21:10
Threshing is here put for the corn threshed, as it is explained in the following words; the act being frequently put for the object, as captivity for the captives, fear for the thing feared, &c., as hath been noted before. And the corn threshed is here metaphorically put for people sorely afflicted and punished, which is oft expressed by threshing, as Isaiah 25:10, Isaiah 41:15 Micah 4:13, &c. This is spoken either,
1. Of the Jews, to whom he now turneth his speech, whom God did grievously thresh and afflict by the Babylonians, and whom he here comforts with these tidings, as if he had said, Though thou wilt be threshed first, yet Babylon shall be threshed last, and most dreadfully, and their threshing shall be thy deliverance. This interpretation is thought necessary, because of the latter clause of the verse, wherewith this is to be joined. Or,
2. Of Babylon. O my threshing; or, thou art my threshing, whom I have undertaken to thresh and punish. And so this is fitly mentioned here, to assure them that this prophecy of Babylon's fall must necessarily be accomplished, because the Almighty was engaged in the work. And this interpretation seems not to be inconsistent with the rest of the verse, as we shall see. The corn of my floor; the corn which I will cause to be threshed upon the floor, Heb. the son of my floor. For the title of son is oft given to lifeless things, as arrows are called the sons of the bow, or of the quiver, Job 5:7, Job 41:28, &c. That which I have heard of the Lord of hosts have I declared; what I have foretold is not my own invention, but the word of God, and therefore shall infallibly come to pass. Unto you; either,
1. Unto you my people, or hearers; for all the prophecies, even concerning other nations, were published to them, and for their use and comfort: or,
2. Unto (or concerning, as this Hebrew particle is sometimes used, as the learned know) you Babylonians, to whom this was in some sort declared, because it was published amongst the Jews, and by their means might easily come to the knowledge of other people, and consequently of the Babylonians. Nor is it unusual for the prophets, in their prophecies delivered to God's people concerning Babylon, by an apostrophe to turn their speech to the Babylonians themselves; of which we have instances, Jeremiah 50:24,31 Jeremiah 51:13,14,25,26.