With his hands joined, he makes a moderate bow to the cross,and goes to the Epistle side where he reads the Communion Verse.
Finally, the whole celebration of mass ends with the thanksgiving, the people rejoicing for having received the mystery (and this is the meaning of the singing after the Communion); and the priest returning thanks by prayer, as Christ, at the close of the supper with His disciples, "said a hymn" (Matthew 26:30). (St. Thomas Aquinas, ST III, q. 83, a. 4, resp.)
Then he turns to the people (if the Blessed Sacrament is reserved on the altar, he goes to the middle to do this), and says:
Dóminus vobíscum.
as he did before the first Oratio or Collect.
At Oremus he makes a slight bow to the cross, raises his hands as usual and recites the Post Communion, and the Oratio super populum if there is one. As he concludes this prayer (immediately before the Per Dominum), he closes the book, unless a proper Gospel is yet to be read.
At Per Dominum nostrum, he joins his hands; and at Jesum Christum, he goes to the middle––if there is only one prayer. But if there is more than one prayer, the priest does not close the book or go to the middle until the Jesum Christum of the last prayer has been said.
Having finished the Postcommunion, the priest again turns to the people and says, Dominus vobiscum, desiring that when they depart from the temple they may not depart from our Lord. And the people again reply, Et cum spiritu tuo, for even after the Mass the giver of holiness must continue to perform spiritual works and not bodily ones for the sake of the people. And by this mutual salutation that indicates their communion, the Mass is accomplished.(St. Albert the Great, qtd. in The Mass and the Saints, p. 195)
Having finished the Postcommunion, the priest again turns to the people and says, Dominus vobiscum, desiring that when they depart from the temple they may not depart from our Lord. And the people again reply, Et cum spiritu tuo, for even after the Mass the giver of holiness must continue to perform spiritual works and not bodily ones for the sake of the people. And by this mutual salutation that indicates their communion, the Mass is accomplished.(St. Albert the Great, qtd. in The Mass and the Saints, p. 195)
After the communion chant, the priest turns to the altar with glad face and with hands apart and prayers the prayer called the Postcommunion. It is so called because it seeks the perfection of communion. From what is received here beneath the veil that covers and hides it will be received openly in the beatitude of heaven.(St. Albert the Great, qtd. in The Mass and the Saints, p. 194)
After the communion chant, the priest turns to the altar with glad face and with hands apart and prayers the prayer called the Postcommunion. It is so called because it seeks the perfection of communion. From what is received here beneath the veil that covers and hides it will be received openly in the beatitude of heaven.(St. Albert the Great, qtd. in The Mass and the Saints, p. 194)
At the middle, he turns to the people and extending his hands, says:
After the acolyte has replied, the priest with hands joined and still facing the people, says:
After which, he turns back to the altar by turning to his left.
If the Gloria in excelsis was not said, the priest does not say Ite, missa est; instead, as soon as he has said Dominus vobiscum, he turns back to the altar, facing which he says: Benedicamus Domino.
It is the general pratice in the Order to say the Placeat Tibi like the Aufer a nobis is said. The priest makes a profound bow toward the cross, with his hands joined; in this position he recites the Placeat Tibi.
After propitiabile, he places his hands on either side of the corporal and kisses the altar (without making a cross on it.) As he continues: Per Christum, etc., he stands erect, joining his hands.
From this phrase, the mass [missa] derives its name, because the priest sends [mittit] his prayers up to God through the angel, as the people do through the priest. or else because Christ is the victim sent [missa] to us: accordingly the deacon on festival days "dismisses" the people at the end of the mass, by saying: "Ite, missa est," that is, the victim has been sent [missa est] to God through the angel, so that it may be accepted by God. (St. Thomas Aquinas, ST III, q. 83, a. 4, ad 9)
From this phrase, the mass [missa] derives its name, because the priest sends [mittit] his prayers up to God through the angel, as the people do through the priest. or else because Christ is the victim sent [missa] to us: accordingly the deacon on festival days "dismisses" the people at the end of the mass, by saying: "Ite, missa est," that is, the victim has been sent [missa est] to God through the angel, so that it may be accepted by God. (St. Thomas Aquinas, ST III, q. 83, a. 4, ad 9)
Turning to the people, he blesses them, saying in the moderate voice: Benedictio Dei, etc., and at the same time he makes over the people a sign of the cross.
He makes this sign, with his eyes cast down, his left hand on his breast, his right hand upright, with the fingers joined and the little finger toward the people.
et Fílii, The priest turns to his right to the altar (making a complete circle), and goes to the Gospel corner.
Saying Dominus vobiscum in a moderate voice, he traces a cross on the altar, (or, on the missal if it is there).
At Initium he makes the same crosses as he did at the first Gospel,
and he stands in the same diagonal way but with his hands joined before his breast. But if the Gospel is proper, the joined hands rest on the missal.
At the words et verbum caro factum est, he genuflects (placing his hands on the altar) and at et habitavit he rises.
The Gospel ended, the priest blesses himself
and returns to the middle.
Finally, the whole celebration of mass ends with the thanksgiving, the people rejoicing for having received the mystery (and this is the meaning of the singing after the Communion); and the priest returning thanks by prayer, as Christ, at the close of the supper with His disciples, "said a hymn" (Matthew 26:30). (St. Thomas Aquinas, ST III, q. 83, a. 4, resp.)