You rightly point out that the comparison between the stream and the river [in Isaiah 8:6-8] is a comparison between kingdoms and the nature and disposition by which they rule, as seen in 2Sam 22:3-4 & Ps 72:4, 6, as gentle and just, as over against the arbitrary will of unjust man. The principles by which the two kingdoms are regulated are decisive for peace or wrath, not only ultimately, but all along the way. So if one will not choose the slowly / gently flowing waters of Shiloah, the peace of divine rule, then the overwhelming waters of the great river, Euphrates will flood all the Land (wrath). We were just talking about this in our last two Saturday evening sessions.
As noted by Kimchi’s commentary, the Davidic throne, for all its weaknesses and deficiencies, is the one sanctioned and ordained by God and the Word of prophecy. Thus, to cast off that kingdom to form another was no small thing, even from the inception of the division.
In Isa 7-8, the very survival of David’s line, and therefore the promise, was in great jeopardy, as the confederated kings of Syria and Israel had conspired to set a puppet king upon the throne of Judah. All seemed bleak and hopeless, but Isaiah showed unwavering faith in the impregnability of the unconditional promise made to David that also guaranteed the ultimate, if not always the immediate, future of Jerusalem, as the eternal city of the great King, the divinely established centerpiece and symbol of the kingdom of God promised to come on earth.
This unconditional promise to David’s seed does not guarantee temporal peace to his natural descendants but eternal peace to his spiritual descendants, that is, to all the spiritual seed of the greater David (see Ps 89). Nor does the certainty of the continuance and preservation of David’s natural line according to the flesh secure against disaster. Obviously, the sure survival of David’s seed does not guarantee individual election, or we might say, ‘personal regeneration’. What it does guarantee is a corporate election that in turn guarantees preservation of the line of the physical line of promise until the “Seed” (personal) should come.
In Him is the promise made sure to all His spiritual seed (corporate), not only of the Jew but of all the seed of true, Abrahamic faith. But even after the personal Seed has come in the twofold nature of Christ, the promise is short of complete fulfillment until Christ is formed in the Jewish survivors of the unequaled tribulation, so that now, all of the nation, as born in one day, can inherit the Land forever, because of an everlasting righteousness from which they will not again go back, because it is not theirs but God’s. That is the mystery and the glory of the New Covenant. The New Covenant is NOT a new start; it’s a new nature!
Israel’s hope, the divine guarantee of a New and Everlasting Covenant, is based on the hope of a spiritual resurrection that must precede the national and bodily resurrection. It is based on the predetermination of God to raise, quicken, and transform what has first been brought down and emptied of its own power.
This raising up by the Spirit depends on nothing of man but on ‘the God who raises the dead’. It is not based on any righteousness, merit, or ground of standing in the fallen and corrupt creature but in God’s own righteousness alone, as perfectly realized only in His uniquely begotten Son.
The incarnation and the New Covenant in Jesus’ blood means that, from the beginning, the only righteousness that God can accept is His own. This righteousness that belongs to God alone is mediated by faith alone, not as its cause but its instrument, since it too is no less a gift, lest any man should boast.
Israel’s hope, the hope of a New Covenant that is sure and everlasting and because it does not depend on man (as foreshore in Abraham’s deep sleep) is based on the God who raises the dead, as He quickens at once and in one day the surviving remnant that will know Him, one and all, from that day and forward. How shall this be? Like all heirs of the New Covenant, they will be born of the Word of God and therefore in union with His divine nature. What then of the danger of falling?
How will “all Israel”, from the least to the greatest, be secure from lapsing and exposing themselves again to curse and exile? How indeed! It because of the New Covenant, which imparts the divine nature. Only because of an everlasting righteousness that is not one’s own can “all Israel” be assured of an abiding righteousness that will not fade or fail, so that now, at last, they can inherit the Land forever, so that “never again” will the children of wickedness afflict them as before (2Sam 7:10; Amos 9:15).
To live in this now revealed, New Covenant is to be in the unconditional, everlasting covenant of peace and righteousness, despite all present dangers, because it is to be on the resurrection side of the promise, as raised up and seated with Him in His triumphant Ascension over all principality and power.
The gospel reveals this everlasting life as no longer waiting for the age to come, as the Jew would see it on the other side of the great transitional day of the Lord. Rather, the powers of that still coming age have arrived in the presence and resurrection power of the Spirit, albeit only in part, as first fruits, earnest, and seal of all that remains.
The conditions and warnings, the danger of apostasy, and the necessity of perseverance in faith cannot defeat the New Covenant. All these very real perils only prove and find out whether the faith by the which we overcome is indeed ‘born of God. It must be so, because it is an inviolable divine principle that “whatsoever is born of God overcomes the world” (). The faith of God’s elect must necessarily overcome, precisely because ‘whatsoever is born of God overcomes the world’. That is what all that comes against our faith is ordained to find out. Only by this rule is our overcoming not credited to anything as generated by ourselves but the unmixed gift of grace, so that to Him alone be all glory.
The proof and evidence of all is perseverance in true holiness, not by mere human resolve, but by the power and resilience of His indwelling life, the life of the resurrection. Those who have this life are partakers of His divine nature, the indwelling seed of the woman, the evidence of reality being that inviolable principle of both nature and the Spirit that the seed will necessarily produce fruit (in some real measure) “after its own kind”.
I like the way you paired Ps 46:2-5 with the slow and un-overwhelming, but ever faithful stream of Shiloah is being made a symbol of that spiritual stream of endless divine life that makes glad the heavenly city (comprised of all His saints, that will, of course, first be realized and vindicated here on earth before it’s heavenly counterpart comes down onto the new earth). Never saw that connection but must imagine that that’s exactly what the Psalmist had in mind in his comparison.