Revelation 9:14
saying to the sixth angel the one having the trumpet, Loose the four angels which have been bound at the great river Euphrates.
Revelation 16:12
And the sixth poured out his bowl upon the great river Euphrates; and his water was dried up, that the way of the kings who are from the rising of the sun may be prepared.
Revelation 7:1
And after this I saw four angels standing on the four corners of the earth, holding the four winds of the earth, that the wind should not blow upon the earth, nor the sea, nor upon any tree.
Revelation 8:2
And I saw the seven angels who stood before God; and seven trumpets were given unto them.
Revelation 8:6
And the seven angels, those having the seven trumpets, prepared themselves that they should sound.
Revelation 9:15
And the four angels were loosed, who were prepared for an hour, and a day, and a month, and a year, that they should slay the third part of the men.