The holy Maid and Virgin Mother of God was this vessel, so she was proclaimed by the Archangel Gabriel as full of grace (Lk. 1:28), being the chosen one among the chosen, blameless, undefiled and worthy to contain the person of the God-Man and to collaborate with Him. Therefore God pre-ordained her before all ages, chose her from among all that had ever lived, and deemed her worthy of more grace than anyone else, making her the holiest of saints, even before her mysterious childbearing. For that reason, He graciously willed that she should make her home in the Holy of Holies, and accepted her as His companion to share His dwelling from her childhood. He did not simply choose her from the masses, but from the elect of all time, who were admired and renowned for their piety and wisdom, and for their character, words and deeds, which pleased God and brought benefit to all.
-- Gregory Palamas