Revelation 16:12
And the sixth angel poured out his vial upon the great river Euphrates; and its water was dried up, that the way of the kings from the east might be prepared.
Revelation 9:14
saying to the sixth angel, who had the trumpet, Let loose the four angels, that are bound by the great river Euphrates.
Revelation 7:2
And I saw another angel which ascended from the east, having the seal of the living God: and he cried with a loud voice to the four angels, to whom it was given to hurt the earth and the sea,
Revelation 11:14
The second wo is past, and behold the third wo is coming quickly.
Revelation 17:15
And he said unto me, The waters which thou sawest, whereon the harlot sitteth, are people, and multitudes, and nations, and tongues.