On the feast of the Immaculate Conception we welcome the dawn of the day as the herald of the ardently desired coming of the Sun of Justice i.e., of the birth of Our Savior, to which Mary”s feast is a beautiful preparatory festival. Hence the feast fits admirably into the time of Advent. The stronger our longing for the divine child, the more rapturous is our joy in the Mother of God. The All holy could not but be born of a most pure virgin. “I will greatly rejoice in the Lord, and my soul shall be joyful in my God” – thus the Church has Mary pray. The Epistle depicts God”s wisdom, to which Mary most nearly approaches: “He that shall find me shall find life, and shall have salvation from the Lord.” May we not say this of our Blessed Lady “whose name is Mary,” and to whom the angel said, “Hail, Mary, full of grace; the Lord is with thee; blessed art thou among women”? The Church brings the mass to a beautiful close: “May the sacraments which we have received, O Lord our God, repair in us the wounds of that sin from which Thou didst in a singular manner preserve the Immaculate Conception of Blessed Mary.
(Source: The New Roman Missal, Rev. F. X. Lasance)