This feast’s texts have a series of divergences relative to the Roman missal. The MAss is essentially the Missae de S. Mariae in Sabbato in Tempore Adventus (usually known as the Rorate Mass) with some variations.
The rubrics prescribe that conventual Mass be said in choro afterTerce; during Lent the Mass of the feria extra choro and after None.
The Introit, the well known Rorate caeli, in this case is:
Rorate caeli desuper, et nubes pluant iustum: aperiatur terra, et germinet Salvatorem.
V/ Et iustitia oriatur simul: ego Dominus creavi eum.
V/ Gloria Patri.
Drop down dew, ye heavens, from above, and let the clouds rain the just: let the earth be opened, and bud forth a saviour.
V/ And let justice spring up together: I the Lord have created him.
The Bragan missal presents us with the following Tract:
Ave, Maria, gratia plena, Dominus tecum.
V/ Benedicta tu in mulieribus, et benedictus fructus ventris tui.
V/ Ecce concipies et paries filium: et vocabitur nomen eius Emmanuel.
V/ Spiritus Sanctus superveniet in te, et virtus Altissimi obumbrabit tibi. Ideoque et quod nascetur ex te Sanctum, vocabitur Filius Dei.
Hail Mary, the Lord is with thee.
V/ Blessed art thou among women, and blessed is the fruit of thy womb.
V/ Behold thou shalt conceive, and shalt bring forth a son; and his name shall be called Emmanuel.
V/ The Holy Ghost shall come upon thee, and the power of the most High shall overshadow thee. And therefore also the Holy which shall be born of thee shall be called the Son of God.
In case the feast falls within Paschaltide, Gradual and Tract are to be substituted by:
V/ Angelus Domini descendit de caelo: et accedens revolvit lapidem: et sedebat super eum. Alleluia, alleluia.
V/ Ecce virgo concipiet et pariet filium Iesum Christum.
V/ The angel of the Lord came down from heaven, and came and rolled back the stone , and sat upon it. Alleluia, alleluia.
V/ Behold, a virgin shall conceive and bear a son, Jesus Christ.
The Preface of is not that of the Blessed Virgin, but that of the Nativity.
We shall look at the Blessed Virgin’s Votive Masses later on, after the Proprium de Tempore feasts have been exhausted.
It is quite interesting the choice of the Preface in the Bragan Missal. While a Marian feast, Jesus is at the centre of it; Mary points to her Son. The choice of preface seems to me to indicate all the more that the Incarnation started on this day; that God become man, that he is “born”, from the moment of His conception.
Perhaps this is related (even if only indirectly) with the jewish tradition that ended up making its way into the early Christians’ beliefs – that the prophets died on their anniversary. Believing that the 14th of Nisan, the day Jesus was crucified, coincided with March 25th, the Annunciation began to be celebrated on this day. Jesus would have been conceived on MArch 25th and died on March 25th (if you add 9 months to it you get… December 25th).