“At thy right hand there are pleasures for evermore” (Ps. 16:11)
“And the sixth angel sounded, and I heard a voice from the four horns of the golden altar which is before God, Saying to the sixth angel which had the trumpet, Loose the four angels which are bound in the great river Euphrates. And the four angels were loosed, which were prepared for an hour, and a day, and a month, and a year, for to slay the third part of men” (Rev. 9:13–15).
When the sixth angel sounded his trumpet, the Roman legions were released, described here under the figure of four angels of destruction. A voice came from the four horns of the gold altar, which means that the command for this to happen now was all within the divine order and plan. Remember that the martyred saints had prayed from this same altar, and now their prayer is being answered (8:3). God’s answer was already prepared. That is what we see in v. 15 also—the angels of destruction that were loosed had been prepared down to the minute. They were released then, at that moment in history, and not before. This was a scheduled event, a timed event (Dan. 9:24-26). They were prepared for the hour, the day, the month, and the year. This was no accident, no happenstance.
They were released to come across the Euphrates, which was the northeast border of the Promised Land. The 10th Legion, part of the destroying force, had been located on the Euphrates. Josephus records the Roman presence there (Wars 7.1.3). This had long been a troublesome border for the Jews—the Assyrians had come across it, as had the Babylonians, and the Persians. Now the Romans. The number of the invading army is translated literally as 200 million (v. 16), but the Greek is myriads of myriads. As Larry Ball points out, this is like our number gazillion. An innumerable host swarmed in to surround Jerusalem.
And all this fits with what Jesus had predicted would happen, and all within one generation. “Verily I say unto you, This generation shall not pass, till all these things be fulfilled” (Matt. 24:34). Not only so, but Jesus had also taught us that the destruction of Jerusalem was one of the central themes of all Old Testament prophecy—meaning that the apocalyptic imagery that John uses for it in Revelation is hardly overdone. “For these be the days of vengeance, that all things which are written may be fulfilled” (Luke 21:22).