And the number of the army of the horsemen - It is to be observed here that the strength of the army seemed to be cavalry. In the former plagues there is no distinct mention of horsemen; but here what struck the beholder was the immense and unparalleled number of horsemen.
Were two hundred thousand thousand - A thousand thousand is one million, and consequently the number here referred to would be 200 million. This would be a larger army than was ever assembled, and it cannot be supposed that it is to be taken literally. That it would be a very large host - so large that it would not be readily numbered - is clear. The expression in the original, while it naturally conveys the idea of an immense number, would seem also to refer to some uniqueness in the manner of reckoning them. The language is, “two myriads of myriads” - δύο μυριάδες μυριάδων duo muriades muriadōn. The myriad was ten thousand. The idea would seem to be this. John saw an immense host of cavalry. They appeared to be divided into large bodies that were in some degree separate, and that might be reckoned by ten thousands. Of these different squadrons there were many, and to express their great and unusual numbers he said that there seemed to be myriads of them - two myriads of myriads, or twice ten thousand myriads. The army thus would seem to be immense - an army, as we should say, to be reckoned by tens of thousands.
And I heard the number of them - They were so numerous that he did not pretend to be able to estimate the number himself, for it was beyond his power of computation; but he heard it stated in these round numbers, that there were “two myriads of myriads” of them.