Synopsis of the Books of the Bible, by John Nelson Darby, [1857-62], at sacred-texts.com
We have the prophetic song, which is based on the foreknown fall of the people. First, it declares the perfectness of Jehovah, whatever may take place; it is Israel who have corrupted themselves (compare Psa 22:3. Christ can say, "Why?") At the same time (Deu 32:8) we have an all-important declaration; namely, that God, in His government of the world, had made Israel the centre, and had arranged the nations of the earth, in their various localities, as having respect to the bounds of Israel as being the first object of those ways. For His earthly people are Jehovah's portion, His inheritance upon earth. But Jeshurun (Israel) waxed fat, and kicked, and forsook the Rock of his strength. Consequently God moves them to jealousy with those that are not a people. It is the call of the Gentiles, according to Rom 10:19.
The judgment, nevertheless, falls upon Israel, so that God would have destroyed them, had not the glory of His name hindered Him, for the Gentiles proved themselves perfectly wicked. Then, the people being distressed, without strength and without hope, He remembers them, and finally takes vengeance on their enemies, those idolatrous Gentiles. But, though avenging Himself, it is then that, having restored His people Israel, He will cause the Gentiles to rejoice in Him.
This principle is true already; but the testimony it furnishes will be fully accomplished when Israel is again restored to the enjoyment of the promises; when God will manifest His mercy towards His land, as well as towards His people. The whole course of His dealings, in respect of the people who form the centre of His ways upon earth, is thus fully brought out. Afterwards, Moses puts obedience (the great end of this book, Israel being placed under the condition of obedience for continuance in the enjoyment of the promises) before them again, and reminds them that thereby they would prolong their days in the land which they were going up to possess.
At last poor Moses has to go up Mount Nebo, to see the land into which he cannot enter, not having answered the requirement of the glory of God in the wilderness, nor sanctified His name by faith. It is the unavoidable consequence of the just government of God towards a servant-I mean under the law. He does not get into the enjoyment of the promise. A single fault deprives him of it.