Pope St. John Paul II
“In a certain sense Mary lived her Eucharistic faith even before the institution of the Eucharist, by the very fact that she offered her virginal womb for the Incarnation of God’s Word. The Eucharist, while commemorating the passion and resurrection, is also in continuity with the incarnation. At the Annunciation Mary conceived the Son of God in the physical reality of his body and blood, thus anticipating within herself what to some degree happens sacramentally in every believer who receives, under the signs of bread and wine, the Lord’s body and blood.”
Source: Pope St. John Paul II, Papal Encyclical: Ecclesia De Eucharista, 4/17/2003