Referring to the Euphrates, which was turned into a different channel, close to Babylon, by Cyrus, who thereby took the city. “The deep” is applied to Euphrates as “sea” (Jer 51:32, Jer 51:36). “Rivers” refers to the artificial canals from the Euphrates made to irrigate the country; when it was turned off into a different bed (namely, a lake, forty miles square, which was originally formed to receive the superfluous water in an inundation), the canals became dry.