Misericordias Domini in aeternum cantabo.

These words of the Church at Easter re-echo in the fullness of their prophetic content the words that Mary uttered during her visit to Elizabeth, the wife of Zechariah: "His mercy is...from generation to generation." At the very moment of the Incarnation, these words open up a new perspective of salvation history. After the resurrection of Christ, this perspective is new on both the historical and the eschatological level. From that time onwards there is a succession of new generations of individuals in the immense human family, in ever-increasing dimensions; there is also a succession of new generations of the People of God, marked with the Sign of the Cross and of the resurrection and "sealed" with the sign of the Paschal Mystery of Christ, the absolute revelation of the mercy that Mary proclaimed on the threshold of her kinswoman's house: "His mercy is...from generation to generation."

Mary is also the one who obtained mercy in a particular and exceptional way, as no other person has. At the same time, still in an exceptional way, she made possible with the sacrifice of her heart her own sharing in revealing God's mercy. This sacrifice is intimately linked with the cross of her Son, at the foot of which she was to stand on Calvary. Her sacrifice is a unique sharing in the revelation of mercy, that is, a sharing in the absolute fidelity of God to His own love, to the covenant that He willed from eternity and that He entered into in time with man, with the people, with humanity; it is a sharing in that revelation that was definitively fulfilled through the cross. No one has experienced, to the same degree as the Mother of the crucified One, the mystery of the cross, the overwhelming encounter of divine transcendent justice with love: that "kiss" given by mercy to justice.104 No one has received into his heart, as much as Mary did, that mystery, that truly divine dimension of the redemption effected on Calvary by means of the death of the Son, together with the sacrifice of her maternal heart, together with her definitive "fiat."

Pope John Paul II, Dives in Misericordia