When Isaiah (Ch. lxi.) uses such phrases as, _trees of righteousness_, _garments of praise_, _garments of salvation_, it is manifest that he cannot mean literal trees or literal garments; the figurative and spiritual import expressed by the epithet affixed to each, namely righteousness, salvation and praise, is the only one that can be given to them. When the same prophet (Ch. lx.) foretelling the glory of the Messiah’s reign, by the conversion of the Gentiles, says _The abundance __ of the sea shall be converted unto thee; the forces of the Gentiles shall come unto thee_, it is evident that the sea does not mean the literal sea, but figuratively the Gentile nations, as afterwards expressed. When he styles the Messiah’s kingdom, _Zion, the city of the Lord, whose walls shall be called salvation, and whose gates praise_; a spiritual and not a literal city must be intended. When, changing the metaphor, he calls the city _a bride_ (Ch. lxii, 5,) or describes it _as a woman in labour, and bringing forth a male child_, (Ch. lxvi. 6. 8.) it is clear that all these expressions must be metaphorical; _the mountain, the city, the bride and the mother_, being alike used to express the same object; and that object, as the context declares, the spiritual glory of the Messiah’s reign; splendid in righteousness, abundant in salvation. Although the spiritual import of these expressions appears self-evident; while the context may satisfy the Christian that these chapters foreshow the nature of the Messiah’s kingdom, metaphorically styled by the prophets, _the Zion of God, His holy mountain, the heavenly Jerusalem, &c._, terms which alone bespeak its spirituality; yet have we moreover the direct sanction and authority of the Apostles Paul and John for thus understanding them. St. Paul, when comparing the advantages of the two covenants, and contrasting the rigorous severity of the law, with the indulgent mildness of the gospel, borrows these very metaphors from the prophets, calling the former Mount Sinai, and the latter Mount Zion. (Heb. xii. 18.) _For ye are not come_, says he, _to the mountain that might be touched, and that burned with fire, nor unto blackness and darkness and tempest, &c._ _But ye are come unto Mount Zion, and unto the city of the living God, the heavenly Jerusalem, and to an innumerable company of Angels._ _To the general assembly and church of the first-born, which are written in heaven, &c._ Here we see _Mount Sinai_, from which the law was delivered, figuratively used to signify the Old Covenant; and _Mount Zion_, and _the Heavenly Jerusalem_ to signify the New Covenant,—called also the _general assembly and church of the first-born_; that is of the regenerate through Christ.