The priest prepares himself by a prayer, said quietly, that he may fruitfully receive Christ’s Body and Blood. The faithful do the same, praying silently. The priest next shows the faithful the Eucharistic Bread, holding it above the paten or above the chalice, and invites them to the banquet of Christ. Along with the faithful, he then makes an act of humility using the prescribed words taken from the Gospels.
It is most desirable that the faithful, just as the priest himself is bound to do, receive the Lord’s Body from hosts consecrated at the same Mass and that, in the instances when it is permitted, they partake of the chalice (cf. no. 283), so that even by means of the signs Communion will stand out more clearly as a participation in the sacrifice actually being celebrated.73Cf. Sacred Congregation of Rites, Instruction Eucharisticum mysterium, On the worship of the Eucharist, 25 May 1967, nos. 31, 32; Sacred Congregation for the Discipline of the Sacraments, Instruction Immensae caritatis, 29 January 1973, no. 2: AAS 65 (1973), pp. 267-268.
While the priest is receiving the Sacrament, the Communion chant is begun. Its purpose is to express the communicants’ union in spirit by means of the unity of their voices, to show joy of heart, and to highlight more clearly the “communitarian” nature of the procession to receive Communion. The singing is continued for as long as the Sacrament is being administered to the faithful.74Cf. Sacred Congregation for the Sacraments and Divine Worship, Instruction Inestimabile donum, 3 April, 1980, no. 17: AAS 72 (1980), p. 338. If, however, there is to be a hymn after Communion, the Communion chant should be ended in a timely manner. Care should be taken that singers, too, can receive Communion with ease.
In the dioceses of the United States of America there are four options for the Communion chant: (1) the antiphon from The Roman Missal or the Psalm from the Roman Gradual as set to music there or in another musical setting; (2) the seasonal antiphon and Psalm of the Simple Gradual; (3) a song from another collection of psalms and antiphons, approved by the United States Conference of Catholic Bishops or the diocesan Bishop, including psalms arranged in responsorial or metrical forms; (4) a suitable liturgical song chosen in accordance with no. 86. This is sung either by the choir alone or by the choir or cantor with the people. If there is no singing, however, the Communion antiphon found in the Missal may be recited either by the faithful, or by some of them, or by a lector. Otherwise the priest himself says it after he has received Communion and before he distributes Communion to the faithful.
When the distribution of Communion is finished, as circumstances suggest, the priest and faithful spend some time praying privately. If desired, a psalm or other canticle of praise or a hymn may also be sung by the entire congregation.
To bring to completion the prayer of the People of God, and also to conclude the entire Communion Rite, the priest says the Prayer after Communion, in which he prays for the fruits of the mystery just celebrated. In the Mass only one prayer after Communion is said, which ends with a shorter conclusion; that is, If the prayer is directed to the Father: Per Christum Dominum nostrum (Through Christ our Lord); If it is directed to the Father, but the Son is mentioned at the end: Qui vivit et regnat in saecula saeculorum (Who lives and reigns forever and ever); If it is directed to the Son: Qui vivis et regnas in saecula saeculorum (You live and reign forever and ever). The people make the prayer their own by the acclamation, Amen.