General Instruction of the Roman Missal: Chapter IV, The Different Forms of Celebrating Mass
IV. Some General Norms for All Forms of Mass
Veneration of the Altar and the Book of the Gospels
273According to traditional practice, the altar and the Book of the Gospels are venerated by means of a kiss. Where, however, a sign of this kind is not in harmony with the traditions or the culture of some region, it is for the Conference of Bishops to establish some other sign in its place, with the consent of the Apostolic See.
Genuflections and Bows
274A genuflection, made by bending the right knee to the ground, signifies adoration, and therefore it is reserved for the Most Blessed Sacrament, as well as for the Holy Cross from the solemn adoration during the liturgical celebration on Good Friday until the beginning of the Easter Vigil.
During Mass, three genuflections are made by the priest celebrant: namely, after the showing of the host, after the showing of the chalice, and before Communion. Certain specific features to be observed in a concelebrated Mass are noted in their proper place (cf. nos. 210-251).
If, however, the tabernacle with the Most Blessed Sacrament is present in the sanctuary, the priest, the deacon, and the other ministers genuflect when they approach the altar and when they depart from it, but not during the celebration of Mass itself.
Otherwise all who pass before the Most Blessed Sacrament genuflect, unless they are moving in procession.
Ministers carrying the processional cross or candles bow their heads instead of genuflecting.
275A bow signifies reverence and honor shown to the persons themselves or to the signs that represent them. There are two kinds of bows: a bow of the head and a bow of the body.
A bow of the head is made when the three Divine Persons are named together and at the names of Jesus, of the Blessed Virgin Mary, and of the Saint in whose honor Mass is being celebrated.
A bow of the body, that is to say a profound bow, is made to the altar; during the prayers Munda cor meum (Almighty God, cleanse my heart) and In spiritu humilitatis (Lord God, we ask you to receive); in the Creed at the words Et incarnatus est (by the power of the Holy Spirit . . . and became man); in the Roman Canon at the words Supplices te rogamus (Almighty God, we pray that your angel). The same kind of bow is made by the deacon when he asks for a blessing before the proclamation of the Gospel. In addition, the priest bows slightly as he speaks the words of the Lord at the consecration.
Incensation
276Thurification or incensation is an expression of reverence and of prayer, as is signified in Sacred Scripture (cf. Ps 141 [140]:2, Rev 8:3).
Incense may be used if desired in any form of Mass:
During the Entrance procession;
At the beginning of Mass, to incense the cross and the altar;
At the Gospel procession and the proclamation of the Gospel itself;
After the bread and the chalice have been placed upon the altar, to incense the offerings, the cross, and the altar, as well as the priest and the people;
At the showing of the host and the chalice after the consecration.
277The priest, having put incense into the thurible, blesses it with the sign of the Cross, without saying anything.
Before and after an incensation, a profound bow is made to the person or object that is incensed, except for the incensation of the altar and the offerings for the Sacrifice of the Mass.
The following are incensed with three swings of the thurible: the Most Blessed Sacrament, a relic of the Holy Cross and images of the Lord exposed for public veneration, the offerings for the sacrifice of the Mass, the altar cross, the Book of the Gospels, the Paschal Candle, the priest, and the people.
The following are incensed with two swings of the thurible: relics and images of the Saints exposed for public veneration, which should be done, however, only at the beginning of the celebration, after the incensation of the altar.
The altar is incensed with single swings of the thurible in this way:
If the altar is freestanding with respect to the wall, the priest incenses walking around it;
If the altar is not freestanding, the priest incenses it while walking first to the righthand side, then to the left.
The cross, if situated on or near the altar, is incensed by the priest before he incenses the altar; otherwise, he incenses it when he passes in front of it.
The priest incenses the offerings with three swings of the thurible or by making the sign of the cross over the offerings with the thurible before going on to incense the cross and the altar.
The Purification
278Whenever a fragment of the host adheres to his fingers, especially after the fraction or the Communion of the faithful, the priest is to wipe his fingers over the paten or, if necessary, wash them. Likewise, he should also gather any fragments that may have fallen outside the paten.
279The sacred vessels are purified by the priest, the deacon, or an instituted acolyte after Communion or after Mass, insofar as possible at the credence table. The purification of the chalice is done with water alone or with wine and water, which is then drunk by whoever does the purification. The paten is usually wiped clean with the purificator.
Care must be taken that whatever may remain of the Blood of Christ after the distribution of Communion is consumed immediately and completely at the altar.
280If a host or any particle should fall, it is to be picked up reverently. If any of the Precious Blood is spilled, the area where the spill occurred should be washed with water, and this water should then be poured into the sacrarium in the sacristy.
Communion under Both Kinds
281Holy Communion has a fuller form as a sign when it is distributed under both kinds. For in this form the sign of the Eucharistic banquet is more clearly evident and clear expression is given to the divine will by which the new and eternal Covenant is ratified in the Blood of the Lord, as also the relationship between the Eucharistic banquet and the eschatological banquet in the Father’s Kingdom.[105]
282Sacred pastors should take care to ensure that the faithful who participate in the rite or are present at it are as fully aware as possible of the Catholic teaching on the form of Holy Communion as set forth by the Ecumenical Council of Trent. Above all, they should instruct the Christian faithful that the Catholic faith teaches that Christ, whole and entire, and the true Sacrament, is received even under only one species, and consequently that as far as the effects are concerned, those who receive under only one species are not deprived of any of the grace that is necessary for salvation.[106]
They are to teach, furthermore, that the Church, in her stewardship of the Sacraments, has the power to set forth or alter whatever provisions, apart from the substance of the Sacraments, that she judges to be most conducive to the veneration of the Sacraments and the well-being of the recipients, in view of changing conditions, times, and places.[107] At the same time, the faithful should be encouraged to seek to participate more eagerly in this sacred rite, by which the sign of the Eucharistic banquet is made more fully evident.
283In addition to those cases given in the ritual books, Communion under both kinds is permitted for:
Priests who are not able to celebrate or concelebrate Mass;
The deacon and others who perform some duty at the Mass;
Members of communities at the conventual Mass or “community” Mass, along with seminarians, and all who are engaged in a retreat or are taking part in a spiritual or pastoral gathering.
The diocesan Bishop may establish norms for Communion under both kinds for his own diocese, which are also to be observed in churches of religious and at celebrations with small groups. The diocesan Bishop is also given the faculty to permit Communion under both kinds whenever it may seem appropriate to the priest to whom, as its own shepherd, a community has been entrusted, provided that the faithful have been well instructed and there is no danger of profanation of the Sacrament or of the rite’s becoming difficult because of the large number of participants or some other reason.
In all that pertains to Communion under both kinds, the Norms for the Distribution and Reception of Holy Communion under Both Kinds in the Dioceses of the United States of America are to be followed (see nos. 27-54).
284When Communion is distributed under both kinds:
The chalice is usually administered by a deacon or, when no deacon is present, by a priest, or even by a duly instituted acolyte or another extraordinary minister of Holy Communion, or by a member of the faithful who, in case of necessity, has been entrusted with this duty for a single occasion;
Whatever may remain of the Blood of Christ is consumed at the altar by the priest or the deacon or the duly instituted acolyte who ministered the chalice. The same then purifies, wipes, and arranges the sacred vessels in the usual way.
Any of the faithful who wish to receive Holy Communion under the species of bread alone should be granted their wish.
285For Communion under both kinds the following should be prepared:
If Communion from the chalice is carried out by communicants’ drinking directly from the chalice, a chalice of a sufficiently large size or several chalices are prepared. Care should, however, be taken in planning lest beyond what is needed of the Blood of Christ remains to be consumed at the end of the celebration.
If Communion is carried out by intinction, the hosts should be neither too thin nor too small, but rather a little thicker than usual, so that after being dipped partly into the Blood of Christ they can still easily be distributed to each communicant.
286If Communion of the Blood of Christ is carried out by communicants’ drinking from the chalice, each communicant, after receiving the Body of Christ, moves and stands facing the minister of the chalice. The minister says, Sanguis Christi (The Blood of Christ), the communicant responds, Amen, and the minister hands over the chalice, which the communicant raises to his or her mouth. Each communicant drinks a little from the chalice, hands it back to the minister, and then withdraws; the minister wipes the rim of the chalice with the purificator.
287If Communion from the chalice is carried out by intinction, each communicant, holding a communion-plate under the chin, approaches the priest who holds a vessel with the sacred particles, a minister standing at his side and holding the chalice. The priest takes a host, dips it partly into the chalice and, showing it, says, Corpus et Sanguis Christi (The Body and Blood of Christ). The communicant responds, Amen, receives the Sacrament in the mouth from the priest, and then withdraws.