Isa 54:1-17. The Fruit of Messiah's Sufferings, and of Israel's Final Penitence at Her Past Unbelief (Isa 53:6): Her Joyful Restoration and Enlargement by Jehovah, Whose Wrath Was Momentary, but His Kindness Everlasting.
Israel converted is compared to a wife (Isa 54:5; Isa 62:5) put away for unfaithfulness, but now forgiven and taken home again. The converted Gentiles are represented as a new progeny of the long-forsaken but now restored wife. The pre-eminence of the Hebrew Church as the mother Church of Christendom is the leading idea; the conversion of the Gentiles is mentioned only as part of her felicity [Horsley].
1. Sing—for joy (Zep 3:14).
barren—the Jewish Church once forsaken by God, and therefore during that time destitute of spiritual children (Isa 54:6).
didst not bear—during the Babylonian exile primarily. Secondarily, and chiefly, during Israel's present dispersion.
the children—the Gentiles adopted by special grace into the original Church (Isa 54:3; Isa 49:20, 21).
than … married wife—than were her spiritual children, when Israel was still a married wife (under the law, before the Babylonian exile), before God put her away [Maurer]. So Paul contrasts the universal Church of the New Testament with the Church of the Old Testament legal dispensation, quoting this very passage (Ga 4:27). But the full accomplishment of it is yet future.