27. (Isa 54:1).
      thou barren--Jerusalem above: the spiritual Church of the Gospel, the fruit of "the promise," answering to Sarah, who bore not "after the flesh": as contrasted with the law, answering to Hagar, who was fruitful in the ordinary course of nature. Isaiah speaks primarily of Israel's restoration after her long-continued calamities; but his language is framed by the Holy Spirit so as 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 trammeled Israel, for she then had no spiritual children of the Gentiles.
      break forth--into crying.
      cry--shout for joy.
      many more--Translate as Greek, "Many are the children of the desolate (the New Testament Church made up in the greater part from the Gentiles, who once had not the promise, and so was destitute of God as her husband), more than of her which hath an (Greek, 'THE') husband (the Jewish Church having GOD for her husband, Isa 54:5; Jer 2:2)." Numerous as were the children of the legal covenant, those of the Gospel covenant are more so. The force of the Greek article is, "Her who has THE husband of which the other is destitute."

JFB.