Before — The whole verse is expressive of a great and sudden salvation, which God would work for his church, like the delivery of a woman, and that of a man — child, before her travail, and without pain. Doubtless it refers to the coming of Christ, and the sudden propagation of the gospel.
Related Commentaries of Isaiah 66:7
Isaiah 66:7
7 Before she travailed, she brought forth; before her pain came, she was delivered of a man child.