8:10 And the third angel sounded, and there fell from heaven a great star, and it fell on the third part of the rivers - It seems Afric is meant by the rivers; (with which this burning part of the world abounds in an especial manner;) Egypt in particular, which the Nile overflows every year far and wide. ln the whole African history, between the irruption of the barbarous nations into the Roman empire, and the ruin of the western empire, after the death of Valentinian the Third, there is nothing more momentous than the Arian calamity, which sprung up in the year 315. It is not possible to tell how many persons, particularly at Alexandria, in all Egypt, and in the neighbouring countries, were destroyed by the rage of the Arians. Yet Afric fared better than other parts of the empire, with regard to the barbarous nations, till the governor of it, whose wife was a zealous Arian, and aunt to Genseric, king of the Vandals, was, under that pretence, unjustly accused before the empress Placidia. He was then prevailed upon to invite the Vandals into Afric; who under Genseric, in the year 428, founded there a kingdom of their own, which continued till the year 533. Under these Vandal kings the true believers endured all manner of afflictions and persecutions. And thus Arianism was the inlet to all heresies and calamities, and at length to Mahometanism itself. This great star was not an angel, (angels are not the agents in the two preceding or the following trumpet,) but a teacher of the church, one of the stars in the right hand of Christ. Such was Arius. He fell from on high, as it were from heaven, into the most pernicious doctrines, and made in his fall a gazing on all sides, being great, and now burning as a torch. He fell on the third part of the rivers - His doctrine spread far and wide, particularly in Egypt. And on the fountains of water - wherewith Afric abounds.

Revelation 8:10 Parallel Commentaries

An Advance Step in the Royal Programme
(Revelation, Chapters iv. and v.) "We are watching, we are waiting, For the bright prophetic day; When the shadows, weary shadows, From the world shall roll away. "We are watching, we are waiting, For the star that brings the day; When the night of sin shall vanish, And the shadows melt away. "We are watching, we are waiting, For the beauteous King of day; For the chiefest of ten thousand, For the Light, the Truth, the Way. "We are waiting for the morning, When the beauteous day is dawning, We are …
by S. D. Gordon—Quiet Talks on the Crowned Christ of Revelation

His Future Work
The Lord Jesus Christ, who finished the work on earth the Father gave Him to do, who is now bodily present in the highest heaven, occupying the Father's throne and exercising His priesthood in behalf of His people, is also King. To Him belongeth a Kingdom and a kingly Glory. He has therefore a kingly work to do. While His past work was foretold by the Spirit of God and His priestly work foreshadowed in the Old Testament, His work as King and His glorious Kingdom to come are likewise the subjects …
A. C. Gaebelein—The Work Of Christ