These changes [i.e. communion under two kinds] have made of the eucharistic banquet and the faithful fulfillment of Christ’s command a clearer and more vital symbol. At the same time in recent years a fuller sharing in the eucharistic celebration through sacramental communion has here and there evoked the desire to return to the ancient usage of depositing the eucharistic bread in the hand of the communicant, he himself then communicating, placing it in his mouth.
Indeed, in certain communities and in certain places this practice has been introduced without prior approval having been requested of the Holy See, and, at times, without any attempt to prepare the faithful adequately.
It is certainly true that ancient usage once allowed the faithful to take this divine food in their hands and to place it in their mouths themselves.
It is also true that in very ancient times they were allowed to take the Blessed Sacrament with them from the place where the holy sacrifice was celebrated. This was principally so as to be able to give themselves Viaticum in case they had to face death for their faith.
However, the Church’s prescriptions and the evidence of the Fathers make it abundantly clear that the greatest reverence was shown the Blessed Sacrament, and that people acted with the greatest prudence. Thus, “let nobody … eat that flesh without first adoring it” As a person takes (the Blessed Sacrament) he is warned: “…receive it: be careful lest you lose any of it.” “For it is the Body of Christ.”
Further, the care and the ministry of the Body and Blood of Christ was specially committed to sacred ministers or to men specially designated for this purpose: “When the president has recited the prayers and all the people have uttered an acclamation, those whom we call deacons distribute to all those present the bread and wine for which thanks have been given, and they take them to those who are absent.”
Soon the task of taking the Blessed Eucharist to those absent was confided to the sacred ministers alone, so as the better to ensure the respect due to the sacrament and to meet the needs of the faithful. Later, with a deepening understanding of the truth of the eucharistic mystery, of its power and of the presence of Christ in it, there came a greater feeling of reverence towards this sacrament and a deeper humility was felt to be demanded when receiving it. Thus the custom was established of the minister placing a particle of consecrated bread on the tongue of the communicant.
This method of distributing holy communion must be retained, taking the present situation of the Church in the entire world into account, not merely because it has many centuries of tradition behind it, but especially because it expresses the faithful’s reverence for the Eucharist. The custom does not detract in any way from the personal dignity of those who approach this great sacrament: it is part of that preparation that is needed for the most fruitful reception of the Body of the Lord.
Sacred Congregation for Divine Worship – Memoriale Domini (Instruction on the Manner of Distributing Holy Communion) – 29 May 1969