Ite missa est

"Ite, missa est" are the concluding words addressed to the people in the Mass of the Roman Rite. The words are Latin for "Go, it is sent," referring to Communion. Literally, it refers to the distribution of Communion, as "host," "offering" and "Eucharist" are all feminine nouns in Latin. The term "Mass" (in Latin, "missa") derives from this phrase. Until the reforms of 1960, at Masses without the Gloria, "Benedicamus Domino" was said instead.

The response of the people (or, in the Tridentine Mass, of the servers at Low Mass, the choir at Solemn Mass) is "Deo gratias" (Thanks be to God).

The Catholic Encyclopedia states , the word "missa" here is not the participle feminine of "mittere", meaning "sent"; it is a noun, "a substantive of a late form for "missio". There are many parallels in medieval Latin, "collecta, ingressa, confessa, accessa, ascensa" - all for forms in "-io"." [, but since, until the reform of Pope Pius X, saints' feasts came to supplant most Sunday Masses, the Last Gospel on such Sundays was that of the Sunday Mass).

With the reform of Pope Paul VI "Ite, missa est" returned to its function as a dismissal formula. It is omitted if another function follows immediately and the people are therefore not dismissed.

"Ite missa est", not being variable like the Scripture readings and the collect, is part of the Ordinary of the Mass and has always been printed in that part of the Roman Missal. Being sung by an individual (ideally the deacon), not by a choir, it obviously cannot be part of a polyphonic musical setting of the Mass. Only the "Deo gratias" response could be set polyphonically and, because of its brevity, it rarely was, except in some early settings such as Machaut's Messe de Nostre Dame.

The dismissal formulas in other liturgical rites are:
*Ambrosian Rite: "Procedamus in pace" (Let us go in peace). Response: "In nomine Christi" (In the name of Christ).
*Mozarabic Rite: "Solemnia completa sunt in nomine D. N. I. C: votum nostrum sit acceptum cum pace" (The celebration is completed in the name of Our Lord Jesus Christ; may our prayer be accepted with peace). Response: "Deo gratias" (Thanks be to God).
*Apostolic Constitutions: "Go in peace."
*Antiochene, Alexandrian and Byzantine liturgies: "Let us go forth in peace" (said by the deacon). Response: "In the name of the Lord." Then the priest says a short "prayer of dismissal".

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