Expositor's Bible Commentary Commentary Galatians 4:27

"For it is written, Rejoice, thou barren that bearest not; Break forth and cry, thou that travailest not: For more are the children of the desolate than of her that hath the husband." — Galatians 4:27 (ASV)

There is no evidence that the verse Paul now quotes (Isaiah 54:1) was ever associated with the story of Hagar and Sarah and their children; nevertheless, it is highly appropriate. This verse is a prophecy of Jerusalem’s restoration following the years of exile and involves the thought that the blessing of the latter years will be greater than that enjoyed formerly. The pre-exilic Jerusalem and the post-exilic Jerusalem correspond, then, to Paul’s distinction between the earthly and heavenly Jerusalems, and the promise to the blessings of God to Israel under the old covenant as contrasted with the greater blessings to the church under the new covenant. The element common to these verses is the supernatural intervention of God in order to establish Christianity. The new element is the suggestion, soon to be fulfilled, that the numbers of Christians will outnumber those within Judaism.