Saying to the deep. This is generally considered to be an allegorical description of Babylon, and I certainly do not deny that it is included; but yet I cannot think of limiting it to Babylon, for I prefer to view it simply as denoting any unexpected change. He shews that some great revolution will be necessary, as if the people must be drawn out of the depths of the sea, but declares that God will easily surmount every obstacle, for he can easily "make the deep dry, and dry up the rivers." In my opinion he rather appears to allude to that former redemption, (Exodus 14:29,) when the Lord brought the people out of Egypt through the Red Sea; as if he had said, "I did this for your fathers, and therefore you ought to hope for the same thing from me, and not to imagine that a return to your native land shall be closed against you."

That saith to the deep, Be dry - Lowth supposes, that this refers to the fact that Cyrus took Babylon by diverting from their course the waters of the river Euphrates, and thus leaving the bed of the river dry, so that he could march his army under the walls of the city (see the notes at Isaiah. 13; 14) With this interpretation, also, Vitringa, John II Michaelis, Grotius, Rosenmuller, and some others, accord. Gesenius supposes that it is a description of the power of God in general; and some others have referred it to the dividing of the waters of the Red Sea when the Hebrews came out of Egypt, as in Isaiah 43:16-17. The most obvious interpretation is that of Lowth, Vitringa, etc., by which it is supposed that it refers to the drying up of the Euphrates and the streams about Babylon, when Cyrus took the city. The principal reasons for this interpretation are, first, that the entire statement in these verses has reference to the events connected with the taking of Babylon; secondly, that it is strikingly descriptive of the manner in which the city was taken by Cyrus; and thirdly, that Cyrus is expressly mentioned Isaiah 44:28, as being concerned in the transaction here referred to. The word rendered 'deep' (צוּלה tsûlâh) denotes properly anything sunk; the depth of the sea; an abyss. 'But it may be applied to a deep river, and especially to the Euphrates, as a deep and mighty stream. In Jeremiah 51:36, the word 'sea' is applied to the Euphrates:
'I will dry up her sea,
And make her springs dry.'
Cyrus took the city of Babylon, after having besieged it a long time in vain, by turning the waters of the river into a vast lake, forty miles square, which had been constructed in order to carry off the superfluous waters in a time of inundation. By doing this, he laid the channel of the river almost dry, and was thus enabled to enter the city above and below, under the walls, and to take it by surprise. The Septuagint renders the word 'deep' here by Ἀβύσσῳ Abussō - 'Abyss.' The Chaldee, 'Who says to Babylon, Be desolate, and I will dry up your streams.'
I will dry up thy rivers - Referring doubtless to the numerous canals or artificial streams by which Babylon and the adjacent country were watered. These were supplied from the Euphrates, and when that was diverted from its usual bed, of course they became dry.

That saith to the deep, Be dry "Who saith to the deep, Be thou wasted" - Cyrus took Babylon by laying the bed of the Euphrates dry, and leading his army into the city by night through the empty channel of the river. This remarkable circumstance, in which the event so exactly corresponded with the prophecy, was also noted by Jeremiah, Jeremiah 50:38; Jeremiah 51:36.
"A drought shall be upon her waters,
and they shall be dried up: -
I will lay her sea dry
And I will scorch up her springs."
It is proper here to give some account of the means and method lay which the stratagem of Cyrus was effected.
The Euphrates in the middle of the summer, from the melting of the snows on the mountains of Armenia, like the Nile, overflows the country. In order to diminish the inundation, and to carry off the waters, two canals were made by Nebuchadnezzar a hundred miles above the city; the first on the eastern side called Naharmalca, or the Royal River, by which the Euphrates was let into the Tigris; the other on the western side, called Pallacopas, or Naharaga, (נהר אגם nahar agam, The river of the pool), by which the redundant waters were carried into a vast lake, forty miles square, contrived, not only to lessen the inundation, but for a reservoir, with sluices, to water the barren country on the Arabian side. Cyrus, by turning the whole river into the lake by the Pallacopas, laid the channel, where it ran through the city, almost dry; so that his army entered it, both above and below, by the bed of the river, the water not reaching above the middle of the thigh. By the great quantity-of water let into the lake, the sluices and dams were destroyed; and being never repaired afterwards, the waters spread over the whole country below, and reduced it to a morass, in which the river is lost. Ingens modo et navigabilis, inde tenuis rivus, despectus emoritur; et nusquam manifesto exitit effluit, ut alii omnes, sed deficit. "And thus a navigable river has been totally lost, it having no exit from this morass. No wonder then that the geographical face of this country is completely changed;" Mela Jeremiah 3:8; Herod. 1:186, 190; Xenophon, Cyrop. vii.; Arrian vii.

That saith to the (e) deep, Be dry, and I will dry up thy rivers:
(e) He shows that God's work would be no less notable in this their deliverance, than when he brought them out of Egypt, through the sea.

That saith to the deep, be dry,.... The Targum is,
"that saith 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 thy 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.

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" (Jeremiah 51:32, Jeremiah 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.

That saith - That with a word can dry up the sea and rivers, and remove all impediments.