Such was the prophecy pronounced immediately after the Fall, and which is fulfilled on this day when the Virgin is conceived without sin. She crushes the head of the serpent at the very moment she begins to be, for she alone of all the children of men, is untainted by the original sin of our first parents.
Today's feast affords us a moment of reflection on this singular privilege (singular means unique, for she is alone) and on the immense joy of her Immaculate Heart. Today's introit introduces us into the great mystery of Mary's joy with the words "Gaudens gaudebo in Domino et exsultabit anima mea in Deo meo": I will rejoice exceedingly in the Lord and my soul shall exult in my God. What is this to say, if not that it is God's grace alone which gives joy, if not that sin alone is what saddens.
On this blessed day, then, let us ask Mary Immaculate to help us be freed of our sins, in order to find that spiritual joy which comes from the Holy Spirit, and which will lead us to "play before God" (ludens coram eo) like ecstatic little children whose only desire is to sing the praises of the Eternal Father, under whose gaze, with that of our Mother, we delight at all times.