Brakel expects not only a future conversion of the Jewish nation. He also expects a return to the land.
That is important to establish without modern projection: he wrote this centuries before 1948. His reasoning arises from his reading of the prophets, not from a reaction to the modern state of Israel.
His question is literally geographical
In section 32 Brakel asks whether the Jewish nation will be gathered again out of the peoples among whom it is scattered, will dwell in Canaan and whether Jerusalem will be rebuilt. His answer is that he believes this will happen.
But he immediately draws boundaries. He expects no restoration of the old temple service as if the foreshadowing ceremonies must receive their former function again after Christ. He also rejects fantasies of world domination.
Deuteronomy 30
Brakel connects return to God, circumcision of the heart, gathering out of the peoples and return to the land in one future movement. His argument is that the full combination is, according to him, not exhausted in the return from Babylon.
Amos 9
At Amos he stresses the planting in the land and the promise of not being plucked up again. Because Israel was later driven out of the land again after the Babylonian return, Brakel concludes that he still expects a further fulfilment.
Ezekiel 37
Ezekiel 37 too brings together for him soul and body, faith and land: gathering out of the peoples, dwelling in the land, one Shepherd and "David" as King. Brakel identifies this David christologically with the Messiah. For just that reason he does not see restoration of the land and Messianic obedience as two separate events.
Isaiah 62 and Zechariah 2
These texts he uses as additional witnesses of the restoration of Zion and Jerusalem. He then treats, among others, Daniel 9 as an objection. His answer is that the destruction announced there concerns the end of the Jerusalem of that time, not a statement that after that destruction there can never be restoration again.
What this does not prove about today
Here an editorial boundary is necessary. That Brakel expects a future return does not mean that every action or border of the present state of Israel is thereby theologically legitimated. Brakel did not know our political constellation. A biblical promise of the land and the judgement of modern state policy are different questions that may not be joined without argument.
And what should Christians do with that?
Brakel ends surprisingly pastorally. He does not want the reader only to "know" these things. The expectation must form an attitude. His last section therefore becomes the close of our series.