Revelation 16:12
And the SIXTH angel poured out his vial upon the great river Euphrates; and the water thereof was dried up, that the way of the kings of the east might be prepared.
Revelation 9:14
saying to the sixth angel who had the trumpet, "loose the four angels which are bound in the great river Euphrates."
Revelation 7:2
and I saw another angel ascending from the east, having the seal of the living God: and he cried with a loud vioce 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 soon follows.
Revelation 17:15
Then he said to me, the waters which you saw, where the prostitute has her seat, are the people, the multitude, nations, and provinces.