Charles Ellicott Commentary Revelation 16:4

"And the third poured out his bowl into the rivers and the fountains of the waters; and it became blood." — Revelation 16:4 (ASV)

And the third angel . . .—The third vial resembles the second in its effects. As it is poured out on the rivers and springs of waters, they become blood. It is not only the great sea that becomes blood, but all the merry streams and babbling brooks that carry their tribute of water seawards also turn corrupt. And this plague is acknowledged by heavenly voices as a just retribution (Revelation 16:5–7).

The streams and rivers feed the sea. They are the powers and influences that form the great popular sentiment, and these are struck by the same corruption. Men cannot worship worldliness or earthliness without degrading even those who contribute to their instruction, their recreations, and their joys to the same level. When the public taste grows corrupt, literature, for example, will also become corrupt to some degree; the up-flowing tide will colour the down-coming stream.

“The morality of a nation’s art,” writes a modern critic, “always rises to the level of morality in a nation’s manners. Morality takes care of itself, and always revenges any outrage that art may put upon its laws by either lowering the art that so offends, or extinguishing it” (Dallas, Gay Science, Vol. II., 16). This is true in an even wider sense. The loftier powers of imagination, the range of poetical elevation, are cramped and killed in a base, world-worshipping age. The streams of life grow putrid; the fresh and bright gifts of God are polluted when the ocean of public thought is unwholesome.