Mary and Medieval Mysticism
The monastic communities of the day did a great deal to encourage and increase Marian devotion, in part by establishing additional feast days for Mary. In particular, Saturday came to be set apart as a day for commemorating Mary. This decision was based on multiple traditions related to Mary. According to one, because the world was completed on the seventh day and Mary was an essential part of the ultimate plan of redemption, it was appropriate to commemorate Mary on that day.
One of the reasons that the seventh day seemed fitting as a day to commemorate Mary was related to the Genesis account. According to Genesis, after God created the world, he rested on the seventh day. Likewise, it was sometimes said that, when the infant Christ came into the world, he was able to find rest in the arms of his mother.
symbolism
Saint Alcuin was a Benedictine monk who was the Minister of Education. He was attached to the court of Charlemagne, and under his direction, each day of the week came to commemorate and symbolize a different event in Scripture. A Mass was to be celebrated on each day, and two were to be celebrated for Mary on Saturday.
The Venerable Bede, an eighth-century English monk who was a famed historian and theologian, wrote some of the earliest Western sermons devoted to Mary. A twelfth-century devotee of Mary, Saint Bernard of Clairvaux, who served as Abbot of Cistercian Monastery for thirty-eight years, also wrote beautiful and influential sermons about the Virgin Mary.

