19. their--A, B, C and Aleph read, "the power of the horses."
      in their mouth--whence issued the fire, smoke, and brimstone (Re 9:17). Many interpreters understand the horsemen to refer to the myriads of Turkish cavalry arrayed in scarlet, blue, and yellow (fire, hyacinth, and brimstone), the lion-headed horses denoting their invincible courage, and the fire and brimstone out of their mouths, the gunpowder and artillery introduced into Europe about this time, and employed by the Turks; the tails, like serpents, having a venomous sting, the false religion of Mohammed supplanting Christianity, or, as ELLIOTT thinks, the Turkish pachas' horse tails, worn as a symbol of authority. (!) All this is very doubtful. Considering the parallelism of this sixth trumpet to the sixth seal, the likelihood is that events are intended immediately preceding the Lord's coming. "The false prophet" (as Isa 9:15 proves), or second beast, having the horns of a lamb, but speaking as the dragon, who supports by lying miracles the final Antichrist, seems to me to be intended. Mohammed, doubtless, is a forerunner of him, but not the exhaustive fulfiller of the prophecy here: Satan will, probably, towards the end, bring out all the powers of hell for the last conflict (see on Re 9:20, on "devils"; compare Re 9:1, 2, 17, 18).
      with them--with the serpent heads and their venomous fangs.

JFB.