And a mighty angel,.... Not Christ, nor one of the ministering spirits, but some man or set of men, perhaps the same with him in Rev 18:1 took up a stone like a great millstone, and cast it into the sea; just as Jeremiah took a stone and bound it to his book after he had read it, and cast it into the river Euphrates, as a sign and token of the destruction of old Babylon, Jer 51:63 saying, thus with violence shall that great city be thrown down, and shall be found no more at all; which is expressive of the utter destruction of Rome, and of the violence, force, and power with which it will be destroyed, and of the suddenness and swiftness of its destruction, and of the irrecoverableness of its state and condition.