There is a great variety of senses also about this mountain of fire cast into the sea. Some by it understand things happening in Judea; but this had been not to have showed John the things which should be, but which had been. Others will have the devil understood; others, the power of the Roman empire; others, some great war stirred up amongst people; others, some notable heresy or heretic; others, some famous persons in the church: but I most like Mr. Mede's notion again here, who understands by this mountain, Rome, the seat of the western empire; great cities being called mountains in Scripture phrase, Isaiah 37:24 Jeremiah 51:25. And the third part of the sea became blood: this phrase speaks only the great effusion of blood upon the taking of Rome by its enemies.
Related Commentaries of Revelation 8:8
Revelation 8:8
8 And the second angel sounded, and as it were a great mountain burning with fire was cast into the sea: and the third part of the sea became blood;