Isaiah 44:27 - Ellicott's Commentary On The Whole Bible

That saith to the deep — i.e., to the Euphrates. The words find a literal fulfilment in the strategical operation by which Cyrus turned the river from its usual bed into the Sepharvaim channel, and thus enabled his soldiers to cross on foot (Herod. i. 191). Symbolically the words may mean simply the destruction of the power of Babylon, of which its river was the emblem. (Comp. Revelation 16:12.)