For it is written, Rejoice, thou barren that bearest not; break forth and cry, thou that travailest not: for the desolate hath many more children than she which hath an husband.
For - proof that 'she is the mother of us' (Isaiah 54:1).
Thou barren - Jerusalem above: the spiritual Gospel Church, the fruit of 'the promise,' answering to Sarah, who bore not "after the flesh;" contrasted with the law, answering to Hagar, who was fruitful in the course of nature. Isaiah speaks primarily of Israel's restoration after her long calamities; but his language is framed by the Holy Spirit to reach beyond this to the spiritual Zion, including not only the Jews, the natural descendants of Abraham and children of the law, but also the Gentiles. The spiritual Jerusalem is regarded as "barren" while the law trammelled Israel; for then she had no spiritual children of the Gentiles.
Break forth - into crying.
Cry - shout for joy.
Manymore. Translate, as Greek, 'Many are the children of the desolate (the New Testament Church, made up mainly of the Gentiles, who once had not the promise, and so without God as her husband), more (the children of both shall be many, but those of the desolate more), than of her which hath an (Greek, THE) husband' (of whom the other is destitute-namely, the Jewish Church having GOD for her husband, Isaiah 54:5; Jeremiah 2:2). Numerous as were the children of the legal covenant, those of the Gospel are more so.