The prayer dates to the 9th century and invokes the Archangel's protection from the enemy of our souls.
In the Raccolta, a collection of prayers that dates to the early 19th century, there is listed a prayer/hymn to St. Michael the Archangel that has a long history, but is now rarely used.
It is entitled “Te splendor et virtus Patris,” and while it has often been set to music, Pope Pius VII in 1817 encouraged the faithful to “say the following hymn [with contrite hearts and devotion], with the antiphon and prayer, in honor of St. Michael the Archangel; to obtain for themselves the mighty aid which his patronage affords to all in the assaults of the enemy of man, and in all temptations, whether in life or at the hour of death.”
The original text of the hymn has been ascribed to Blessed Rabanus Maurus, a Benedictine monk of the 9th century. He is also believed to be the author of the hymn Veni Creator Spiritus.
Below is an English translation of the hymn based on the Latin text found in the Raccolta.
O Jesus, lifespring of the soul,
The Father’s power, and glory bright!
Thee with the angels we extol;
From Thee they draw their life and light.
Thy thousand thousand hosts are spread
Embattled o‘er the azure sky;
But Michael bears Thy standard dread,
And lifts the mighty Cross on high.
He in that sign the rebel powers
Did with their dragon prince expel;
And hurl’d them from the heaven’s high towers
Down like a thunderbolt to hell.
Grant us with Michael still, O Lord,
Against the Prince of Pride to fight;
So may a crown be our reward,
Before the Lamb’s pure throne of light.
To God the Father glory be,
And to his sole-begotten Son;
The same, O Holy Ghost, to Thee,
While everlasting ages run.
Ant. Most glorious Prince, Michael the Archangel, be thou mindful of us; here, and in all places, pray for us to the Son of God most high.
V. I wilt sing praises to Thee, my God, before the Angels.
R. I will adore Thee in Thy holy temple, and praise Thy Name.
Let us pray.
O God, who in the dispensation of Thy providence dost admirably dispose the ministry of angels and of men; mercifully grant that the Holy Angels, who ever minister before Thy throne in heaven, may be the protectors also of our life on earth. Through Jesus Christ our Lord.