Isaiah 11:15 - Ellicott's Commentary On The Whole Bible

The tongue... — Better, as in Joshua 15:2; Joshua 15:5; Joshua 18:19, the “bay” or “gulf.” The “Egyptian sea” is the Gulf of Suez, and the prophet pictures to himself another marvel like the passage of the Red Sea in Exodus 14:22. The “river,” on the other hand, is the word Commonly used for the Euphrates (Genesis 31:21; Joshua 24:2), and that meaning is assigned to it here by most commentators, who refer to Isaiah 44:27 as a parallel. In Isaiah 19:5, however, it is found, as here, in parallelism with the “sea” of Egypt, and as it there refers to the Nile, that meaning may well be accepted here. The prophet describes, in language which almost excludes the thought of a merely literal fulfilment, a renewal of wonders transcending those of the Exodus, and it was natural that his description should bear the local colouring of the region. He contemplates a return from Egypt as much as from Assyria (Isaiah 11:11). On this view the words that follow, “will smite it in the seven streams,” refer naturally enough to the seven mouths that enclose and intersect the Delta of the Nile. On the other view, the words may be interpreted as meaning literally, “I will smite it [Euphrates] into seven streams,” and figuratively, “I will reduce the power of Assyria [or Babylon, as an Assyrian city] to insignificance.”