Revelation 9:13–15

13 And the sixth angel sounded, and I heard a voice from the four horns of the golden altar which is before God, 14 Saying to the sixth angel which had the trumpet, Loose the four angels which are bound in the great river Euphrates. 15 And the four angels were loosed, which were prepared for an hourb, and a day, and a month, and a year, for to slay the third part of men.