It was revealed to Santa Matilde di Hackeborn, a Benedictine nun who died in 1298, as a sure means of obtaining the grace of a good death. Our Lady told her:
“If you want to obtain this grace, recite every day pray Three Hail Marys, to thank the Blessed Sacrament. Trinity of the privileges of which it has enriched me. With the first you will thank God the Father of the Power he has given me, and by virtue of it you will demand that I assist you at the hour of death.
With the second you will thank God the Son of having communicated to me his wisdom, so that I know the Trinity more than all the saints. For it you will ask me that at the hour of death you shine your soul with the lights of faith and turn away from you any ignorance of error.
With the third you will thank the Holy Spirit for having filled me so much with love and goodness that after God I am the most tender and merciful. For this incomparable goodness you will ask me that at the hour of your death I will fill your soul with the sweetness of divine love and change the pains of death for you in sweetness.
At the end of the last century and in the first two decades of the present, the devotion of the Three Hail Mary spread rapidly in various countries of the world for the zeal of a French Capuchin, Fr. Giovanni Battista di Blois, assisted by the missionaries.
It became a universal practice when Leo XIII granted indulgences and prescribed that the Celebrant recite the Three Hail Marys with the people after Holy Mass. This prescription lasted until Vatican Council II.
Pope John XXIII and Paul VI gave a special blessing to those who propagate it.Many Cardinals and Bishops gave impulse to the spread the prayer.
Many Saints were its propagators. Sant ‘Alfonso Maria de’ Liquori, as a preacher, confessor and writer, did not cease to inculcate the good practice. He wanted everyone to adopt it.
St. John Bosco strongly recommended it to his young people. Even the blessed Pio of Pietrelcina was zealous propagator. St. John B. de Rossi, who every day devoted up to ten or twelve hours to the ministry of confessions, attributed to the daily recitation of the Three Hail Mary the conversion of obstinate sinners.
Prayerfully pray every day like this:
Mary, Mother of Jesus and my Mother, defend me from the evil one in life and in the hour of death
for the power that the Eternal Father granted you
for the Wisdom which the Divine Son granted you.
for the Love that the Holy Spirit has given you.