John Gill Commentary Isaiah 44:27

"that saith to the deep, Be dry, and I will dry up thy rivers;" — Isaiah 44:27 (ASV)

That says to the deep, be dry
The Targum is, ``that says to Babylon, be desolate;'' and most interpreters, Jewish and Christian, understand it of Babylon, which was situated in a watery place, by rivers of water, particularly the river Euphrates, and in a low valley:

and I will dry up your rivers ;
some think the allusion is to the stratagem of Cyrus, made use of, under a divine direction, to drain the river Euphrates, and make it passable for his army; by which means he surprised the city of Babylon, and took it: though others think it refers to the drying up of the Red sea and the river Jordan, which are proofs of what God can do, and a periphrasis of his power.