Marked by the priestly piety of the school of Bérulle, Pope Saint Pius X was singularly favourable to the invocation of Our Blessed Lady under the title of Virgo Sacerdos. Already in 1875, Blessed Pius IX had manifested his approval of the same title in a letter addressed to Msgr Oswald Van den Berghe, author of Marie et le Sacerdoce. Saint Pius X was pleased when an Italian translation of this work appeared.
When the Daughters of the Heart of Jesus, founded by Blessed Marie de Jésus Deluil-Martiny, asked for permission to invoke the Mother of God, in their chapels, as Maria Virgo Sacerdos, Saint Pius X wishing to extend the devotion to all the faithful, charged Cardinals Vanutelli and Vivès with composing a prayer that would make this Marian title better known. The prayer appeared, indulgenced by Pope Saint Pius X, on 9 May 1906.
O Mary, Mother of Mercy,
Mother and Daughter of Him who is the Father of mercies
and the God of all consolation (1),
Dispensatrix of all the treasures of thy Son (2),
Minister of God (3),
Mother of Christ, our High Priest,
thou who art both Offerer and Altar together, (4),
Immaculate Temple of the Word of God (5),
Teacher of the Apostles and Disciples of Christ (6),
protect the Supreme Pontiff,
intercede for us and for our priests,
that Jesus Christ the Eternal High Priest
may purify our consciences,
and that we may worthily, and with loving devotion,
approach His sacred banquet.
O Immaculate Virgin,
who not only hast given us Christ the heavenly bread
for the forgiveness of sins (7),
but who art thyself a most acceptable sacrifice offered unto God” (8),
and the glory of priests (9),
and who, as thy most blessed servant Saint Antoninius declares,
“without receiving the Sacrament of Order,
wert full of whatsoever in dignity and grace is given by it”,
thou art therefore rightly acclaimed as “Sacerdotal Virgin” (10).
Look upon us and upon the priests of thy Son,
save us, purify us, and sanctify us,
that we may receive the ineffable treasures of the Sacraments
in a holy manner
and so deserve to obtain
the eternal salvation of our souls. Amen.
Mother of Mercy, pray for us.
Mother of Jesus Christ, the Eternal Priest, pray for us.
Queen of the Clergy, pray for us.
Mary, Sacerdotal Virgin, pray for us.
 Richard of Saint Laurence
 Saint Bernardine
 Saint Bernard of Busto
 Saint Epiphanius
 Abbot Ludovicus Blosius
 Saint Thomas of Villanova.
 Saint Epiphanius
 Saint Andrew of Crete
 Saint Ephrem
 Letter of Blessed Pope Pius IX, 25 August 1873
We grant 300 day of indulgence to one who recites this prayer with piety and devotion.
9 May 1906.
Pius P. P. X.