In the Roman rite and most related local uses, there are three forms of dismissal to be sung or said by the deacon after the postcommunion and final Dominus vobiscum. They are Ite missa est, Benedicamus Domino like in the Office or Requiescant in pace. The third would always be said at Mass of the Dead and the first at Mass when the Gloria is said.
The Sarum rubrics tend to express the rule for the dismissal formula as governed by the number of lessons at Matins and whether the Te Deum is sung. The Roman rite (pre 1962) follows the same principle, since the Gloria is sung at Mass when the Te Deum is sung at Matins. The only vigils at which the Ite missa est is sung are Easter and Pentecost. Benedicamus Domino is said on all weekday ferias, all other vigils, when the Mass Salus Populi is said, Masses of the Cross and all feasts of three lessons, when the Te Deum is not sung at Matins. Our (those of us who use Sarum) main difference from the Roman rite is that minor feasts of saints are celebrated without Gloria, and Benedicamus Domino is said. The ferial weekdays of Paschaltide are just as at any other time of the liturgical year. In the pre-1962 rite, the Benedicamus Domino would be said when violet vestments are worn or green on weekdays. This more sparing use of the Gloria reflects a time when the Gloria was reserved for the Bishop’s mass, as on Maundy Thursday.
Since beginning to use Sarum from about 2008, I see many things as more logical and more in keeping with the rationale than the 1570 Roman rite.
Another question is how to translate Ite missa est for when we say Mass in English. There is no problem for Benedicamus Domino (Let us bless the Lord) and Requiescant in pace (May they rest in peace). No translation seems to be entirely adequate. Ite means the imperative Go. That bit is easy enough. Missa can mean mass or dismissal, sending away. Est is the third person singular in the present tense of the infinitive esse, to be.
Go, dismissal (sending on mission) is – Go, it is the dismissal. It doesn’t seem much. The key to this problem would seem to be in interpreting the word missa as related to missio as collecta for collectio or ascensa for ascensio. It refers to the sending away of the faithful to take to the world what they have have given at Mass. The sending is implicit in Go. For a freer translation, a reason for this sending away could be given, on account of the fact that the Mass is over and people may go home or stay in church for private prayer.
The usual translations given are:
- Go, you are dismissed.
- Depart, the mass is ended.
- Depart, the mass is finished.
- Depart, the congregation is dismissed.
It is on account of this awkwardness that I say Ite missa est in Latin at Mass in English. After all, we say the Κύριε ελέησον in Greek and הַלְּלוּיָהּ (alleluia) in Hebrew. On Good Friday, we have the whole Trisagion in Greek as in the Byzantine Liturgy. So, what cannot be translated is best left untranslated. Indeed, unless saying Mass in the vernacular for pastoral needs, I say Mass entirely in Latin.
The reason why the Benedicamus Domino is used on non-solemn days is that the congregation was not sent away, but encouraged to stay in church for further prayers and devotions. However, the three Roman Ordines of before the tenth century know only Ite missa est, presumably why the Benedicamus Domino was removed from the Roman rite in 1962 and the reformed rites under Paul VI. Evidence of this is the singing of Benedicamus Domino at the end of the Christmas midnight Mass because Lauds follows.
From 1964 in the Roman rite, the Ite missa est was moved to its present position after the blessing, so that they would be the last words the congregation would hear before leaving the church. The Novus Ordo removed the Placeat tibi sancta Trinitas prayer before the final kissing of the altar and placed the blessing immediately after the Postcommunion. The priest would kiss the altar just after the Ite missa est. The reasoning would seem to be logical, except that the blessing is not part of the Mass, but an add-on as was the Placeat. Perhaps old Bugnini could have been more logical and abolished the blessing. There is no blessing at the end of the Sarum Mass. After the Placeat and the final kissing of the altar, the priest crosses himself In nomine Patris, etc. and says the Prologue of St John quietly on his way to the sacristy.