Revelation 16:12
And the sixth poured out his bowl on the river, the great 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, Unbind the four angels bound by the river, the great Euphrates.
Revelation 7:2
And I saw another angel ascend 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 injure the earth and the sea,
Revelation 11:14
The second woe has passed; behold, the third woe comes quickly.
Revelation 17:15
And he said to me, The waters which you saw, where the harlot sits, are peoples and multitudes and nations and tongues.