1 To honor Our Lady's Immaculate Conception, Her perfections and Glories.
2 To honor Our lady's motherhood both human and divine.
3 To honor Our Lady as the Heavenly Spouse of the Holy Spirit .
This devotion started in the 13th century after a revelation to St. Mechtilde of Hackeborn, a German Benedictine nun, to whom Our Lady appeared giving her a simple devotion in which we are to honour the Most Holy Trinity.
One day as she was talking to Our Lady, St. Mechtilde asked to help her at the hour of her death, and our Lady replied:
“Yes, I will; but I want you, on your part, to pray three Hail Marys to me each day.
With the first Hail Mary, you will ask that, just as God the Father raised me up to a throne of glory without equal, making me the most powerful creature in heaven and on earth, so too I may assist you on earth to strengthen you and drive away from you every power of the enemy.
With the second Hail Mary, you will ask that, just as the Son of God filled me with wisdom to such an extent that I have more knowledge of the Holy Trinity than all the Saints, so too may I help you during the last moments of your life, filling your soul with the light of faith and of true wisdom, so that the shadows of error and ignorance may not darken it.
With the third Hail Mary, you will ask that, just as the Holy Spirit filled me with the sweetness of His love, and has made me so loving that, after God, I am the sweetest and most merciful, so also may I help you at the hour of your death, filling your soul with such gentleness of divine love that all the sorrow and bitterness of your death may be changed for you into delight.”
The Virgin Mary promised Saint Mechtilde that whoever would pray three Hail Marys every day would receive her help during life and her special assistance at the moment of death; She said that she would appear to them with such brightness and beauty that the mere sight of her would bring consolation and the joys of heaven.
There was another saint contemporary to St. Metchilde; Saint Gertrude, who also received beautiful knowledge about this devotion of three Hail Maries, this is what happened:
During the vespers of the feast of the Annunciation, and when it was time to sing the Hail Mary, St. Gertrude suddenly saw something like three springs of water emerging from the Hearts of the Father, of the Son, and of the Holy Spirit, which then penetrated the Heart of the Blessed Virgin.
At that instant, she heard a voice that said, “After the Power of the Father, the Wisdom of the Son, and the Tender Mercy of the Holy Spirit, nothing compares to the Power, Wisdom, and Tender Mercy of Mary.”
So we can simply do this devotion as follows:
1 First Hail Mary, we honour the Power of God conferred to the Blessed Virgin Mary, who did the Will of the Father.
2 Second Hail Mary, we honour the Wisdom of God conferred to the Blessed Virgin Mary, who is the seat of Wisdom, Our Lord Jesus Christ whose mother She is.
3 Third Hail Mary, we honour the Love, Charity and Mercy conferred to the Blessed Virgin Mary, as spouse of the Holy Spirit.