Then the sixth angel blew his trumpet, and I heard a voice from the four horns of the golden altar before God,
References for Revelation 9:13
saying to the sixth angel who had the trumpet, "Release the four angels who are bound at the great river Euphrates."
So the four angels were released, who had been held ready for the hour, the day, the month, and the year, to kill a third of humankind.
The number of the troops of cavalry was two hundred million; I heard their number.
And this was how I saw the horses in my vision: the riders wore breastplates the color of fire and of sapphire and of sulfur; the heads of the horses were like lions' heads, and fire and smoke and sulfur came out of their mouths.
References for Revelation 9:17
By these three plagues a third of humankind was killed, by the fire and smoke and sulfur coming out of their mouths.
For the power of the horses is in their mouths and in their tails; their tails are like serpents, having heads; and with them they inflict harm.
The rest of humankind, who were not killed by these plagues, did not repent of the works of their hands or give up worshiping demons and idols of gold and silver and bronze and stone and wood, which cannot see or hear or walk.
And they did not repent of their murders or their sorceries or their fornication or their thefts.