As with all celebrations of the Blessed Virgin, today’s Nativity of Mary ultimately refers to Christ.
The birthday of Our Lady heralds the coming of Our Redeemer. We rejoice at Mary’s arrival in the world because she is the Lord’s chosen who will be the Mother of Christ.
With her birth, salvation history takes a momentous step forward: the birth of her Son draws ever closer. The one from whom the Eternal Word will take His flesh, is now here. God is working out His plan of redemption!
From Dom Gueranger’s Liturgical Year:
Andrew of Crete calls this day a solemnity of entrance, a feast of beginning, whose end is the union of the Word with our flesh; a virginal feast, full of joy and confidence for all.
‘All ye nations, come hither,’ cries St. John Damascene, ‘come every race and every tongue, every age and every dignity, let us joyfully celebrate the birthday of the world’s gladness.’
‘It is the beginning of salvation, the origin of every feast,’ says St. Peter Damian, ‘for behold! The Mother of the Bridegroom is born. With good reason does the whole world rejoice today; and the Church, beside herself, bids her choirs sing wedding songs.’
— Vol. XIV, pp. 148-49.