I AM DOING A NEW THING!

Isa 43:19  Behold, I am doing a new thing! Now it springs forth; do you not perceive and know it and will you not give heed to it? I will even make a way in the wilderness and rivers in the desert.

Remember ye not the former things — But although your former deliverance out of Egypt was in itself a most glorious work, which you ought always to remember and consider; yet this other work, of your deliverance out of Babylon, and those blessings which shall follow upon it, and particularly that of sending the Messiah, shall be so transcendent a favour, that, in comparison thereof, all your former deliverances are scarcely worthy of your remembrance and consideration. See two parallel texts, Jer 16:14-15; Jer 23:5-8. From which passages laid together it appears that this latter deliverance, compared with that out of Egypt, is not to be confined to their restoration from captivity, but to be extended to the consequences thereof, and especially to the redemption of the Messiah. Indeed, otherwise the deliverance from Egypt was more glorious and wonderful, in many respects, than that out of Babylon. 

Behold, I will do a new thing — Such a work as was never yet done in the world. Now it shall spring forth — The Scripture often speaks of things at a great distance of time, as if they were now at hand, to make us sensible of the inconsiderableness of time and all temporal things, in comparison of God and eternal things; upon which account it is said, that a thousand years are in God’s sight but as one day. 

Shall ye not know it? — Certainly, you Jews shall know it by experience, and shall find I do not deceive you with vain hopes. I will make a way in the wilderness, &c. — I will give you direction and provision in the wilderness, where there is commonly no path, and where all necessaries are wanting; which, as it literally speaks of God’s conducting them through the great desert which lay between Babylon and Judea, so it is mystically meant of those spiritual blessings which God, in and through Christ, would confer upon all his people, not the Jews only, but also the Gentiles, who, in prophetical language, are often compared to a wilderness. 

Behold, I will do a new thing,.... A wonderful and unheard of thing, and therefore introduced with a "behold", as a note of admiration; the same with the new thing created in the earth, Jer 31:22, the incarnation of the Son of God; who took flesh of a virgin, appeared in the likeness of sinful flesh, and was made sin and a curse for his people, in order to obtain eternal redemption for them; which blessing, though not newly thought of, resolved on, contrived, and agreed upon, that being from eternity; nor newly made known, or as to the virtue and efficacy of it, which had been from the beginning of the world, yet new as to the impetration of it by the blood and sacrifice of Christ; and may be also called "new", because excellent, it being of a spiritual nature, complete and eternal, and having so many valuable blessings in it, as justification, pardon, and eternal life:

now it shall spring forth; or bud forth as a branch, in a very short time, suddenly, and at once; one of the Messiah's names is that of the Branch; see Zec 3:8,

Jeremiah 23:5   (AMPC).  V5  Behold, the days are coming, says the Lord, when I will raise up to David a righteous Branch (Sprout), and He will reign as King and do wisely and will execute justice and righteousness in the land.

Zechariah 6:12   (AMPC).  V12  And say to him, Thus says the Lord of hosts: [You, Joshua] behold (look at, keep in sight, watch) the Man [the Messiah] whose name is the Branch, for He shall grow up in His place and He shall build the [true] temple of the Lord. [Isa 4:2; Jer 23:5; Jer 33:15; Zec 3:8]

https://www.youtube.com/watch?v=gDfuGb89x_8

shall ye not know it? the Redeemer, and the redemption by him. It was known to them that looked for it, and to whom the Gospel is sent, and the Spirit reveals and applies it; these know the nature of it, own it to be of God, and know their interest in it, and know the author of it, in whom they have believed, by the characters given of him: and as this may have respect to the redemption of Christ, so to the conversion of the Gentiles, and to the grace of God dispensed through Christ to them; when old things passed away, and all things became new; a new covenant of grace was exhibited, a new church state set up, new ordinances appointed, and a new people called to partake of all this, on whom was a new face of things; and wonderful and excellent things were done for them, as follows:

I will even make a way in the wilderness; as there was a way made for the Israelites through the wilderness, which lay between Egypt and Canaan; and through another, which lay between Babylon and Judea; so the Lord would also make a way in the Gentile world, comparable to a wilderness for its barrenness and unfruitfulness, for the Gospel to enter into it, where it should run, and be glorified; where Christ, the way of salvation, should be made known; and where there should be a way for Christians to walk together, in the fellowship of the Gospel:

and rivers in the desert; the doctrines of the Gospel, and the ordinances of it, which should be preached and administered in the Gentile world, before like a desert; and the graces of the Spirit, which should be brought into the hearts of men by means of them; and the large communications of grace from Christ; and the discoveries of the love of God, with the blessings of it; compared to rivers for their abundance, and for the comforting, reviving, and fructifying nature of them.

Behold, I will do a new thing !

It is, of course, quite possible that the novelty is not merely in the circumstances of the deliverance, but extends to all its results, among which is the Messianic kingdom—verily, a "new thing" (see Jer 31:22). Now it shall spring forth; rather, already it is springing up (comp. Isa 42:9). Things, however, are more advanced (to the prophet’s eye) than when that passage was written. Events are shaping themselves—the deliverance approaches. Shall ye not know it? rather, will ye not give heed to it? Will not the exiled people, whom Isaiah addresses, turn their thoughts this way, and let the idea of deliverance take possession of their minds, instead of brooding on past and present sufferings (see Isa 40:30; Isa 41:17; Isa 42:22)? God is about to make a way in the wilderness, and rivers in the desert. As he led his people out of their Egyptian bondage, first through the Red Sea, and then through a "howling wilderness" (Deu 32:10), so now he will "make a way" for them through a still more desolate tract. We are nowhere historically told by what route the Israelites ultimately returned. If they went by Tadmor and Damascus, they must have traversed a most arid and difficult desert. Even if they did not quit the Euphrates till they reached the latitude of Aleppo, still they must have had some wide tracts of wilderness to cross.