Deuteronomy 32:43

Rejoice, O ye nations, [with] his people
Or, "rejoice, ye nations", who are "his" people; so Kimchi and Ben Melech interpret it; the Gentiles, who are the Lord's chosen and covenant people, redeemed and called, and the fulness of them now brought in, and so matter of great rejoicing; or rather, as the Septuagint, which is approved and confirmed by the Apostle Paul, "rejoice, ye Gentiles, with his people", ( Romans 15:10 ) ; and as it is there applied to the then state of the Christian church, when Jews and Gentiles were incorporated and united together; so here it respects future time, when, as the fulness of the Gentiles will be brought in, so the Jews will be converted, and the "loammi", ( Hosea 1:9 ) , will be taken off from them, and they will be reckoned among the people of God; and Jews and Gentiles will be joined together in the same Gospel church state, and so are called upon to rejoice in their common salvation, and in their common blessings and privileges, and particularly for what follows:

for he will avenge the blood of his servants, and will render
vengeance to his adversaries;
by his servants are meant the martyrs of Jesus, whose blood has been shed by antichrist, and the antichristian powers, his adversaries; as the blood of the Waldenses in the valleys of Piedmont, the Albigenses in Spain, and the Petrobrussians in France, the Bohemians in Germany, the Wickliffites, Lollards and the "martyrs" in Queen Mary's days in England, with many others; and when inquisition is made for blood, the blood of those will be found out, and vengeance rendered for it:

and will be merciful unto his land, [and] to his people:
or "will atone for" ^F26, expiate, cleanse, and purge both land and people; clear the whole earth, which is the Lord's, from Mahometanism, Paganism, and Popery, and cover it with the knowledge of the Lord by the everlasting Gospel, which will be preached to all nations; and particularly the land of Canaan, laid under an anathema or curse, as threatened, ( Malachi 4:6 ) ; under which it has lain ever since the destruction of it by the Romans, and has ever since been inhabited by Pagans, Mahometans, and Papists; and, though once a land flowing with milk and honey, has been turned into a barren wilderness, and will thus remain, and Jerusalem, its metropolis, trodden down by the Gentiles, until their times are fulfilled; which now will be, and then it will be restored to its former fruitfulness and fertility, ( Luke 21:24 ) ( Ezekiel 34:25-27 ) ; and will be inhabited by the converted Jews, to whom the Lord will be pacified, upon the foot or Christ's atonement, which now will be made known and applied unto them, with the full and free pardon of all their sins, ( Romans 11:25-27 ) ; and thus ends this most excellent and wonderful song, which is of such a large extent and compass, as to reach from the beginning of the Jewish nation, and before it, to the conversion of the Jews in the latter day; an history of more than four thousand years already; and how long more is yet to come before all in it is fulfilled no man call say.