For this day’s feast, the Introit begins with the famliar Gaudeamus omnes in Domino verse (already seen on the Assumption), only the feast being specified this time is the Nativity, not the Assumption. The Psalm verse is Ps. 47:2. The usual formula for Bragan Introits on certain feasts is followed.
The Collect of the day (or variants thereof) is found in the Sarum, Dominican, Carmelite and certain German rites. The Supplicationem servorum tourum seems to have been a versatile Marian collect, used on a number of the Blessed Virgin’s feasts.
Supplicationem servorum tuorum, Deus, miserator, exaudi, ut qui in Nativitate Dei Genitricis et Virginis Mariae congregamur; eius intercessionibus a te de instantibus periculis eruamur. Per eumdem…Graciously and mercifully hear the plea of Thy servants, O God, so that we who have gathered to celebrate the Nativity of the virgin Mary, Mother of God, may at her intercession be saved by Thee from pressing evils: through the same…
For those curious, here is the general prayer found in the Dominican rite:
Supplicationem servorum tuorum Deus miserator exaudi ut qui in solemnitate Dei Genitricis et Virginis congregamur ejus intercessionibus a te de instantibus periculis eruamur.
The Alleluia presents us with
Nativitas tua, Dei Genetrix Virgo, gaudium attulit universo mundo: quia ex te ortus est sol iustitiae, Christus Deus noster.
Thy birth, O Virgin Mother of God, brought joy to the whole world: for out of thee arose the Sun of Justice, Christ our God.
D. Prosper Gueranger OSB mentions in his The Liturgical Year that both East and West use this same text on this very feast in their services:
“Not only do the Doctors of East and West use similar language in praise of Mary’s birth, but moreover the Latin and Greek Churches sing, each in its own tongue, the same beautiful formula, to close the office of the Feast: “Thy birth, O Virgin Mother of God, brought joy to the whole world: for out of thee arose the Sun of Justice, Christ our God: who, taking off the curse, hath bestowed blessing; and, defeating death, hath given us life everlasting.” (Trope of the dismissal in utroque Vespertino; Magnificat Ant. of 2nd Vespers).”
Here is the Byzantine Troparion:
Your Nativity, O Virgin,Has proclaimed joy to the whole universe!The Sun of Righteousness, Christ our God,Has shone from You, O Theotokos!By annulling the curse,He bestowed a blessing.By destroying death, He has granted us eternal Life.
The Offertory uses the Roman Alleluia.
The Preface used is that of the Blessed Virgin, but with Et te in Nativitate added. If anyone is aware of any other rite where Nativitate is added to the ooreface onthis day, please let us know.
Alma Bracarense 