Thomas Aquinas, on Isa 66:7

“Before she was in labour, she brought forth; before her time came to be delivered, she brought forth a man child.”

“Second, he describes the promise as to abundance of goods. And first, as to the reuniting of the people, setting out the promise, before she was in labor, she brought forth; that is, the children of Jerusalem will be gathered to her suddenly and at the same time, just as if a woman brought forth a child suddenly, without first being in labor, above: the children are come to the birth (Isa 37:3). Mystically, this is interpreted as concerning the labor of the Blessed Virgin, and the labor of the Church in the conversion of the faithful, and the labor of eternal begetting.”

Imported from an open dataset — not yet checked against the printed edition.