Romans 8:23

And not only they, but ourselves also
Not only they Gentiles, but we Jews likewise:

which have the firstfruits of the Spirit:
meaning either the apostles, who were all Jews, and who most of them received the extraordinary gifts of the Spirit on the day of "Pentecost", which was the day of the firstfruits, ( Numbers 28:26 ) ; and to which there seems to be an allusion here; or else the Jewish converts in general: to the Jews the promises of the Messiah were made; to them he first came; the Gospel was first preached unto them, and some of them first believed in Christ; they had the grace of God communicated to them in conversion, which they received as the firstfruits, with respect to an after increase; or in regard to glory, like the firstfruits, grace is of the same kind with glory, and is a pledge and earnest of it; saints judge by grace the firstfruits, what glory is, and therefore long after it; now of these persons thus described it is said,

even we ourselves groan within ourselves;
their groans were inward from their hearts, not hypocritical or were among themselves, common to them all; and that not merely on their own account, the corruptions of their hearts, the sufferings they endured for the sake of the Gospel, and in a longing expectation for the heavenly glory, but also for the conversion of the Gentiles, for which they incessantly laboured, and prayed night and day;

waiting for the adoption, to wit, the redemption of our body.
Adoption is explained by the redemption of the body; and by the one may be known what the other means: by "the redemption of our body" is not meant the redemption of God's elect, body and soul, by the blood and death of Christ, which was already finished; and which the saints, who had received the firstfruits, were partakers of in themselves, and therefore could not be said to be waiting for it: but it designs either the redemption of the natural body, by the resurrection from the dead; when the bodies of the saints will be delivered from that mortality, corruption, weakness, and dishonour, under which they lie in the grave; when they will be refined and spiritualized, and freed from everything which makes them an incumbrance, and an uneasiness to their souls or spirits now; or else the redemption of the mystical body the church, of which the Gentiles make a considerable part, and is to be understood of a deliverance of the church, from the distresses and persecutions it then laboured under; or rather of a making up of the body, the church, by a redemption or deliverance of that part of it, which lay among the Gentiles, from that vanity and bondage of corruption, to which it was subject, into the manifestation and glorious liberty of the sons of God: and then by "adoption" is meant, the special grace of adoption, manifested to the Gentiles in their effectual calling; which the Jews who had received the firstfruits of the Spirit were waiting for, and had good reason to expect, from many prophecies in the writings of the Old Testament; and to which they were the more encouraged, by many appearances of the grace and power of God, attending the ministry of the Gospel among them; and which adoption will be more fully manifested in the resurrection morn; wherefore also the inheritance, which the whole mystical body the church will then enter upon the possession of, may well be called "the adoption", because the saints are adopted to it; adoption gives them the title to it, none but adopted ones will enjoy it; and their enjoyment of it will be the full manifestation and completion of the grace of adoption; this saints are waiting for, both for themselves and others, and it is worth waiting for; for it is "an inheritance incorruptible, undefiled, which fades not away, reserved in the heavens", ( 1 Peter 1:4 ) : and there is good ground to wait for it; it is a bequest of their heavenly Father, who has adopted them; it is a gift of his free grace; it is already in the hands of Christ, with whom they are co-heirs; and they have already the Spirit, as the earnest of it.