Explanation of the Prayers and Ceremonies of Holy Mass, Dom Prosper Guéranger - Ite, missa est

These words are usually translated thus: “Go, the Mass is said.” However, we must here observe that this is not their proper sense. This formula, adopted by the Church, was in general use amongst the Romans, in public assemblies, to announce the termination of the meeting. So, these words: Ite, concio missa est, meant “go, the assembly is dismissed.”

In the early ages, the Holy Sacrifice was never called by our word Missa, the Mass. When the Sacrifice was finished, the assembled faithful were dismissed by the Deacon, in the form usual at all public meetings. Later, the word missa having been adopted, the confusion of ideas became complete, when by the putting of a capital M to this formula, it ended in Ite Missa est, being thus translated amiss: Go, the Mass is said. In Masses at penitential times, in Lent, for example, instead of the Ite Missa est, the Deacon says Benedicamus Domino; the faithful are not dismissed, because it is supposed that they would like to remain longer in prayer, during these days of expiation. The Ite Missa est is consequently a sign of joy, and, as such, it is excluded from Requiem masses: a Song of joy would be out of keeping with a Mass breathing only sadness and supplication

The Ite Missa est having been said, the Priest turns again to the Altar, and bowing somewhat, with his hands joined, he says: Placeat tibi Sancta Trinitas obsequium servtutis meae, et praesta ut Sacrificium, quod oculis tuae majestatis indignus obtuli, tibi sit acceptabile, mihique et omnibus, pro quibus illud obtuli, sit, te miserante, propitiabile. Per Christum Dominum nostrum. Amen. This prayer is a kind of epitome made by the Priest, reminding the Holy Trinity of all he has just been doing, begging acceptance of this Sacrifice, and that it may be profitable to all those for whom he has been praying.