Rejoice, O ye nations - Ye Gentiles, for the casting off of the Jews shall be the means of your ingathering with his people, for they shall not be utterly cast off. (See Romans 15:9, for in this way the apostle applies it). But how shall the Gentiles be called, and the Jews have their iniquity purged? He will be merciful unto his land and to his people, וכפר vechipper, he shall cause an atonement to be made for his land and people; i. e., Jesus Christ, the long promised Messiah, shall be crucified for Jews and Gentiles, and the way to the holiest be made plain by his blood.
The people have long been making atonements for themselves, but to none effect, for their atonements were but signs, and not the thing signified, for the body is Christ; now the Lord himself makes an atonement, for the Lamb of God alone taketh away the sin of the world. This is a very proper and encouraging conclusion to the awfully important matter of this poem.
Israel shall be long scattered, peeled, and punished, but they shall have mercy in the latter times; they also shall rejoice with the Gentiles, in the common salvation purchased by the blood of the Savior of all mankind.
Rejoice, O ye nations, with His people - Some prefer the marginal rendering.
In this profound passage, there is shadowed forth the purpose of God to overrule:
(1) the unbelief of the Jews to the bringing in of the Gentiles; and
(2) the mercy shown to the Gentries to the eventual restoration of the Jews (compare Romans 11:25-36).
The Song closes as it began Deuteronomy 32:1-3, with an invitation to praise. It has reached, through a long series of divine interpositions, its grandest theme in this call to the Gentiles, now pagan no more, to rejoice over God‘s restored people, the Jews.