Hilary of Poitiers
Catena Aurea · Matthäusevangelium 2
And when they were departed, behold, the angel of the Lord appeareth to Joseph in a dream, saying, Arise, and take the young Child and His mother, and flee into Egypt, and be thou there until I bring thee word; for Herod will seek the young Child to destroy Him. When he arose, he took the young Child and His mother by night, and departed into Egypt: And was there until the death of Herod: that it might be fulfilled which was spoken of the Lord by the prophet, saying, Out of Egypt have I called my Son.
The first time when he would teach Joseph that she was lawfully espoused, the Angel called the Virgin his espoused wife; but after the birth she is only spoken of as the Mother of Jesus. As wedlock was rightfully imputed to her in her virginity, so virginity is esteemed venerable in her as the mother of Jesus.