The fourth Sunday of Advent is known to be the "Sunday Rorate". It owes this name to the introit:
Rorate caeli desuper et nubes pluant justum aperiatur terra et germinet Salvatorem
Drizzle, heavens, from on high, and the clouds make it rain the righteous, open the tera and sprout the Savior(Isa . 45:8).
This chant, however, is not exclusive to this Sunday and, in fact, we find it as introitus De festis beatae Virginis (for the feasts of the Blessed Virgin Mary).
But how did he get to the fourth Sunday of Advent?
It must be premised that, in ancient liturgical calendars, "dicitur illa dominica vacans" (that Sunday is called 'empty'). The reason for this was due to the liturgy of the preceding Saturday, which, as we have seen about the third week of Advent, was the day of the Winter Tempora and, in particular, was referred to as "sabbatorum die in XII lectiones" (The Saturday of the 12 readings). It owed this name to a unique liturgy consisting of a Vigil with 12 readings that the pope celebrated at St. Peter's and during which ordinations were also held. This liturgy ended at dawn with a Mass that, in itself, constituted the Sunday celebration that followed the 12-readings Saturday. Consequently, there was no second Mass for that Sunday but it was indicated by a "vacat" (empty). This was before the 8th century as, later, the Eve liturgies were brought forward from the night to Saturday morning making it necessary to have a proper Mass for that Sunday. It began, in this way, to create the formulary for the Fourth Sunday of Advent by taking material that already existed. Anciently, then, there are at least 3 introitutions that medieval sources testify to for this Sunday.
The first, logically, is precisely that of the 12-readings Saturday that constituted that of Sunday.
Veni et ostende nobis faciem tuam domine qui sedes super cherubim et salvi erimus
Come and show us your face, O Lord, who sits on the Chierubim, and we shall be saved (Ps. 80:4, 2)
We find, in some Graduals, the introit:
Memento nostri domine in beneplacito populi tui visita nos in salutari tuo ad videndum in bonitate electorum tuorum in laetitia gentis tuae ut lauderis cum hereditate tua
Remember us, Lord, for the sake of your people, visit us with your salvation, so that we may see the happiness of your elect, enjoy the joy of your people, glory in your inheritance (Ps 106:4-5).
This text is sung, again as the introit, in the Ambrosian liturgy on the Second Sunday of Advent. The Dominican tradition, however, continues to sing it as the introit of the Fourth Sunday of Advent. The Roman Gradual, today, sees it as the introit of the last Wednesday before Christmas.
Finally, we also have the introit Rorate caeli:
This introit, as we have seen, is proper for celebrations of the Virgin Mary and, in particular, for theAnnuntiatio Dominica (Annunciation of the Lord). When the three celebrations of the Tempora of the tenth month (December) were reorganized in the mid-fifth century, this was done with Christmas in mind. The first of these three celebrations then became the Missa aurea beatae Mariae, a votive mass to the Virgin that saw its texts addressed to Christ coming into the world. The introit for this Wednesday of the third week of Advent became, then, also the introit for the fourth Sunday of Advent, and the choice was maintained even after the reform of the Second Vatican Council.
Among the various introductions to the Virgin, the Rorate caeli is probably the one that also best manages to place itself in the Advent season and its medieval theological reading. If Advent, in the Middle Ages, is the time of spring, of this hymn is affirmed:
Et competit tempori veris. Fuit enim in vere: quando enim Deus factus est homo, omnia nova facta sunt.
(Is appropriate for the time of spring. For it was spring when God became man and renewed all things)
What is the Christological reading of this song?
This introit representat ecclesiae tempus, quando venit Christus in Beatam Virginem (represents the time of the Church when Christ descended in the Blessed Virgin). The imperative rorate (rain) is put in the mouth of the angels and prophets and means. "praedicate adventum Domini" (announce the coming of the Lord). Advent is symbolized by the ros, the dew or rain and connects precisely with the image of the promised king sung in Psalm 72: "descendit sicut pluvia in vellus" (He will descend as rain on the grass). The expression "pluant iustum, id est Christum antonomasice" ("rain the Just One" is Christ par excellence). He, the Just One, as rain descends to us and accomplishes three things: changes hearts, quenches thirst and bears fruit. The second part of the introit antiphon sings Mary. The opening earth becomes an allegory of the Virgin Mary when she utters the words, "ecce ancilla Domini" (Behold the handmaid of the Lord. Lk 1:38). That held opened only because of her consensum, (consent), that is, by her "fiat" (be fulfilled). The conclusion: "et germinet Saluatorem" (and germinate the Savior) is his immaculate conception.
In this perspective, then, are to be understood all the hymns proper to this celebration that puts at the center the One who is proclaimed and conceived-Christ.
In particular, the offertory Ave Maria (Lk 1:28) is connected to "When eam Angelus salutavit et de Spiritu Sancto concepit" (when the Angel greeted her and she conceived by the Holy Spirit).
The theme is again taken up by the communion antiphon: "Ecce virgo concipiet et pariet filium et vocabitur nomen ejus Emmanuel" (Behold, the Virgin shall conceive and bear a son, and he shall be called Emmanuel. Is 7:14).
One detail worth noting, in the architecture of this celebration, concerns the theme of the proclamation. It is theincipit of the introit antiphon and the prolix responsory Canite tuba, also from the Fourth Sunday of Advent.
In the background is precisely the.Annutiatio Dominica, a proclaiming of the Lord that runs through the entire liturgical day: from night to day. The closeness of sound climate between the beginnings of these two songs may be why medieval theologians put the Isaiah text of the Rorate into the mouths of angels and preachers. Indeed, the tuba was precisely associated with preaching as Alcuin testifies to us in a letter to Charlemagne where he hurled against the saecularis potestas (the secular power) the catholicae praedicationis tuba (the trumpet of universal preaching).