"This presence of God in Mary is itself the secret of Advent"

"In fact for St Bernard, all the Scriptures harmonize together like the instruments of a great orchestra, and through all these various instruments the One Spirit of God  proclaims one message in different tones, all of them leading up to the final message of the angel to Mary herself in which the entire Old Testament finds its fulfilment . Mary is, in a sense, the Old Testament in herself. She gathers unto herself all the prophecies and all the miracles and reveals their meaning in giving birth to the Divine Word Who was contained and hidden in them.
Present in all creatures by His power, present in reasonable beings as the object of knowledge , present in the saints by the union of love, God now makes Himself present in the bosom of Mary in a totally new and extraordinary manner, united not only to her will but even to her flesh so that He Himself takes flesh of her substance. Jesus is at the same time the Son of God and the Son of Mary. Et si nec totus de Deo nec totus de Virgine, totus tamen Dei et totus Virginis est.

This presence of God in Mary is itself the secret of Advent, the heart of the Mystery, for it is in Mary herself that the Son of God gave us the admirable Sacrament of Advent - Filius tecum as condendum in te mirabile Sacramentum!"

Thomas Merton: The Sacrament of Advent in the Spirituality of St Bernard
from 'Seasons of Celebration' 

Today is the anniversary of Thomas Merton's death in 1968