saying to the sixth angel who had the trumpet, "Release the four angels who are bound at the great river Euphrates."
Revelation 9:14
Surrounding context
9:13 Then the sixth angel sounded: And I heard a voice from the four horns of the golden altar which is before God,
9:14 saying to the sixth angel who had the trumpet, "Release the four angels who are bound at the great river Euphrates."
9:15 So the four angels, who had been prepared for the hour and day and month and year, were released to kill a third of mankind.