Revelation 9:19

“For their power is in their mouth, etc.] In what proceeded out of their mouth, or seethed to do so; in their guns, and what came out of them: and in their tails; which may design their foot soldiers, which were as the tail to their horse, and who sometimes did great service; or their way of fighting when they fled, by casting up arrows into the air, which would fall upon the heads and horses of those that pursued them; or their ambushments, by which they destroyed many; or their perfidious violation of treaties; or it may be their tails may intend the doctrine of Mahomet, the false prophet, who is the tail, (<230915>Isaiah 9:15), for their tails [were] like unto serpents; crooked, crafty,…”

“their--A, B, C and Aleph read, "the power of the horses." in their mouth--whence issued the fire, smoke, and brimstone (Rev 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…”

“For their power is in their mouth - That is, as described in the fire, smoke, and brimstone that proceeded out of their mouths. What struck the seer as remarkable on looking on the symbol was, that this immense destruction seemed to proceed out of their mouths. It was not that they trampled down their enemies; nor that they destroyed them with the sword, the bow, or the spear: it was some new and remarkable power in warfare - in which the destruction seemed to proceed from fire, and smoke, and sulphur issuing from the mouths of the horses themselves. And in their tails - The tails of the horses. This, of course, was something unusual and remarkable in horses, for naturally they have no power…”

“in their tails: Rev 9:10; Isa 9:15; Eph 4:14 Revelation 9:20”