saying to the sixth angel who had the trumpet
The sixth angel is tasked with the release of the four bound angels. We are not told how they are bound nor how they are released. We can assume that both their binding and release involves the direct supernatural power of God and the sixth angel is merely the instrument by which this power is administered. Their binding is most likely similar to that which will be experienced by Satan during the Millennial Kingdom (Rev. Rev. 20:1-3+) and their loosing like that of Satan at the end of the Millennium (Rev. Rev. 20:7+).
release the four angels
These four angels have evidently been reserved in bondage for this special purpose of God. Since there are only four, it is likely that they are a specific group of especially malevolent or powerful angels. Even one angel, in a single night, killed one hundred and eighty-five thousand Assyrians (2K. 2K. 19:35). It appears that these four angels will be assisted in their assignment by an additional demonic army. They probably serve as commanders. The number four speaks of the worldwide effect of their destruction. See Four: the Entire World, the Earth.
Barnhouse takes these to be supernatural powers who, while bound, have actively prevented the passing of evil forces from the east to the west.3 When they are removed, then forces from beyond the Euphrates are allowed to come into the holy land. This seems unlikely on two counts:
at the great river Euphrates
Later, in the sixth bowl judgment, the Euphrates is dried up to prepare the way for the kings of the east to gather to battle against God (Rev. Rev. 16:12-14+). The mention of the Euphrates both here and in Revelation Rev. 16:12+ provides further evidence that Babylon (Rev. Rev. 14:8+; Rev. 16:19+; Rev. 17:5+; Rev. 18:2+, Rev. 18:10+, Rev. 18:21+) is the literal, historical city on the banks of the Euphrates.6
Exactly how they are bound there is a mystery, of course. How anythingparticularly disembodied spiritscould be chained for four thousand years in a flowing river is unknown, to say the least. . . . No doubt God is equal to the needs of the occasion, however, and can bind them in some quite appropriate and effective manner. . . .7
The Euphrates is linked with the most important events in ancient history. On its banks stood the city of Babylon; the army of Necho was defeated on its banks by Nebuchadnezzar; Cyrus the Younger and Crassus perished after crossing it; Alexander crossed it, and Trajan and Severus descended it.Appletons Cyclopedia8
It was near the Euphrates that sin began, the first lie was told, the first murder was committed, and the tower of Babel (the origin of an entire complex of false religions that spread across the world) was built. The Euphrates was the eastern boundary of the Promised Land (Gen. Gen. 15:18; Ex. Ex. 23:31; Deu. Deu. 11:24), and Israels influence extended to the Euphrates during the reigns of David (1Chr. 1Chr. 18:3) and Solomon (Sos. 2:1Chr. 9:26). The region near the Euphrates was the central location of three world powers that oppressed Israel: Assyria, Babylon, and Medo-Persia. It was on the banks of the Euphrates that Israel endured seventy long, bitter, wearisome years of captivity (cf. Ps. Ps. 137:1-4). It is the river over which the enemies of God will cross to engage in the battle of Armageddon (Rev. Rev. 16:12-16+).9
Attention has been abundantly called by commentators to the region of the Euphrates as that place where human sin began and also Satans empire over man; where the first murder was committed; where the first war confederacy was made (Genesis Gen. 14:1); and back of this it is where Nimrod began to be a mighty one in the earth, and where the vast system of Babylonian idolatry, with its trinity of evilfather, mother and son originated, to deceive the whole world by the Satanic fable of the queen of heaven. Here, moreover, as we saw in Zechariah Zec. 5:1, iniquity is to have its last stage on earth (see Revelation Rev. 18:1+ also).10
4 John MacArthur, Revelation 1-11 : The MacArthur New Testament Commentary (Chicago, IL: Moody Press, 1999), Rev. 9:14.
5 Unless we allow ourselves the luxury of departing from the text and imagining it to describe helicopter gunships and other modern weaponsthus falling into a trap similar to that of the Historicist Interpretation.
6 There is another intriguing possibility, of course. Maybe the Euphrates mentioned here is the antediluvian Euphrates rather than the Babylonian Euphrates. It is barely possible that, deep in the earth, remains the underground storage chamber which controlled the primeval flow into the garden of Eden. Though most of these caverns broke up with their fountains (controlled exit conduits) erupted to help produce the Flood, or at least in the earths isostatic readjustments after the Flood, it must may be that the primeval source of Edens rivers is still intact.Henry Morris, The Revelation Record (Wheaton, IL: Tyndale House Publishers, 1983), Rev. 9:14.
9 MacArthur, Revelation 1-11 : The MacArthur New Testament Commentary, Rev. 9:14.