How does this happen? The presence of the risen Christ in the Eucharist is an inexhaustible mystery that the Church can never fully explain in words. We must remember that the triune God is the creator of all that exists and has the power to do more than we can possibly imagine. As St. Ambrose said: “If the word of the Lord Jesus is so powerful as to bring into existence things which were not, then a fortiori those things which already exist can be changed into something else” (De Sacramentis, IV, 5-16). God created the world in order to share his life with persons who are not God. This great plan of salvation reveals a wisdom that surpasses our understanding. But we are not left in ignorance: for out of his love for us, God reveals his truth to us in ways that we can understand through the gift of faith and the grace of the Holy Spirit dwelling in us. We are thus enabled to understand at least in some measure what would otherwise remain unknown to us, though we can never completely comprehend the mystery of God.
from the Congregation for Divine Worship, Rome; 22 November 2008...
Questions: What about giving blessings to people who come forward in the Communion line but who are not receiving Communion? Should a priest, deacon or an extraordinary minister of Holy Communion give the person a blessing instead? What if a person who is not receiving Communion presents himself with arms crossed over the chest, during the regular administration of Communion?
Answers:
The liturgical blessing of the Holy Mass is properly given to each and to all at the conclusion of the Mass, just a few moments subsequent to the distribution of Holy Communion.
Lay people, within the context of Holy Mass, are unable to confer blessings. These blessings, rather, are the competence of the priest.
Furthermore, the laying on of a hand or hands — which has its own sacramental significance, inappropriate here — by those distributing Holy Communion, in substitution for its reception, is to be explicitly discouraged.
The Apostolic Exhortation Familiaris Consortio n. 84, “forbids any pastor, for whatever reason to pretext even of a pastoral nature, to perform ceremonies of any kind for divorced people who remarry.” To be feared is that any form of blessing in substitution for communion would give the impression that the divorced and remarried have been returned, in some sense, to the status of Catholics in good standing.
In a similar way, for others who are not to be admitted to Holy Communion in accord with the norm of law, the Church’s discipline has already made clear that they should not approach Holy Communion nor receive a blessing. This would include non-Catholics and those envisaged in can. 915 (i.e., those under the penalty of excommunication or interdict, and others who obstinately persist in manifest grave sin).
In summary:
Extraordinary Ministers of Holy Communion (always laity) cannot give sacramental blessings within Mass.
Young children, who have not yet received first Holy Communion accompanying their parents in the Communion line may come with their arms crossed over their chests as a signal to the minister that they are not receiving Communion and as an expression of the child’s reverence for the Blessed Sacrament; but not as a sign they want a blessing. This reverent gesture of a young child is laudable and appropriate.
It should be clear to all that the priest’s blessing at the conclusion of Mass includes everyone, and that there should not be separate blessings for any person during the Communion rite.
BLESSINGS AT HOLY COMMUNION: The distribution of Holy Communion is not a time for blessing or touching a child or other persons who do not receive Communion. If someone comes forward in the Communion procession and does not receive communion the Ordinary or extraordinary minister of Holy Communion may simply say, “Receive the Lord in your heart,” with no blessing or touching of the person.