His seed also will I make to endure for ever,.... Not a race of kings from David, which ended at the Babylonish captivity; not the natural seed of David, not the Messiah himself, who sprung from him, but the Messiah's spiritual seed, which were given him by the Father, adopted through him, regenerated by his Spirit and grace, begotten through his Gospel, and the ministry of it, and born again in his church, and to whom he stands in the relation of the everlasting Father, Isa 9:6.
The "enduring" of these "for ever" may denote the final perseverance of particular believers; which may be concluded from the relation of Christ, as an everlasting Father to them, who therefore must continue as his children; from his affection to them, from which there can be no separation; from their security in and by him, being in his hand, and in his heart; from their adoption, which is never revoked, being sons they are no more servants; from their regeneration of incorruptible seed; and from the nature of faith, which can never be lost: they that trust in the Lord are as Mount Zion, which endures for ever, Ps 125:1 or it may be expressive of the duration of the church of Christ in general, throughout all periods of time, notwithstanding the malice and opposition of men and devils against it; see Mt 16:18,and his throne as the days of heaven; a phrase signifying a great length of time, De 11:21 yea, invariable constancy and duration, Jer 31:25 and indeed the throne of Christ is for ever and ever, and will be when the present earth and heavens are fled away, Ps 45:6.