Revelation 9:14
saying to the sixth angel, who had the trumpet, Loose the four angels who are bound by the great river Euphrates.
Revelation 16:12
And the sixth poured forth his vial upon the great river Euphrates; and its water was dried up, that a way might be prepared for the kings from the rising of the sun.
Revelation 7:1
And, after these things, I saw four angels, standing at the four corners of the earth, holding the four winds of the earth, that the wind might not blow upon the earth, nor upon the sea, nor on any tree.
Revelation 8:2
And I saw the seven angels which stood before God; and seven trumpets were given to them.
Revelation 8:6
And the seven angels who had the seven trumpets, prepared themselves to 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, to kill a third part of men.