9:17 Having breastplates as of fire, and of jacinth, and brimstone. Or, bright red, blue and yellow. These are the colors observed.
The heads of the horses [were] as the heads of lions. Strength and fierceness are implied.
And out of their mouths issued fire and smoke and brimstone. This is a destroying power. It might well describe the use of gunpowder. One looking at a distance would see the flash of fire, and the smoke, apparently coming from the horses' heads, would smell the brimstone odor, and would see the destructive effect.
9:13-21 The sixth angel sounded, and here the power of the Turks seems the subject. Their time is limited. They not only slew in war, but brought a poisonous and ruinous religion. The antichristian generation repented not under these dreadful judgments. From this sixth trumpet learn that God can make one enemy of the church a scourge and a plague to another. The idolatry in the remains of the eastern church and elsewhere, and the sins of professed Christians, render this prophecy and its fulfilment more wonderful. And the attentive reader of Scripture and history, may find his faith and hope strengthened by events, which in other respects fill his heart with anguish and his eyes with tears, while he sees that men who escape these plagues, repent not of their evil works, but go on with idolatries, wickedness, and cruelty, till wrath comes upon them to the utmost.
