On the worship of the Eucharist outside of Mass:
25. The worship of the Eucharist outside of the Mass is of inestimable value for the life of the Church. This worship is strictly linked to the celebration of the Eucharistic Sacrifice. The presence of Christ under the sacred species reserved after Mass – a presence which lasts as long as the species of bread and of wine remain (Cf. Ecumenical Council of Trent, Session XIII, Decretum de ss. Eucharistia, Canon 4: DS 1654.) – derives from the celebration of the sacrifice and is directed towards communion, both sacramental and spiritual. (Cf. Rituale Romanum: De sacra communione et de cultu mysterii eucharistici extra Missam, 36 (No. 80).) It is the responsibility of Pastors to encourage, also by their personal witness, the practice of Eucharistic adoration, and exposition of the Blessed Sacrament in particular, as well as prayer of adoration before Christ present under the Eucharistic species. (Cf. Rituale Romanum: De sacra communione et de cultu mysterii eucharistici extra Missam, 38-39 (No. 80).)
It is pleasant to spend time with him, to lie close to his breast like the Beloved Disciple (cf. Jn 13:25) and to feel the infinite love present in his heart. If in our time Christians must be distinguished above all by the “art of prayer”, (Novo Millennio Ineunte 32) how can we not feel a renewed need to spend time in spiritual converse, in silent adoration, in heartfelt love before Christ present in the Most Holy Sacrament? How often, dear brother and sisters, have I experienced this, and drawn from it strength, consolation and support!
This practice, repeatedly praised and recommended by the Magisterium, (Mysterium Fidei) is supported by the example of many saints. Particularly outstanding in this regard was Saint Alphonsus Liguori, who wrote: “Of all devotions, that of adoring Jesus in the Blessed Sacrament is the greatest after the sacraments, the one dearest to God and the one most helpful to us”. (Visite al SS. Sacramento e a Maria Santissima, Introduction: Opere Ascetiche, Avellino, 2000, 295.) The Eucharist is a priceless treasure: by not only celebrating it but also by praying before it outside of Mass we are enabled to make contact with the very wellspring of grace. A Christian community desirous of contemplating the face of Christ in the spirit which I proposed in the Apostolic Letters Novo Millennio Ineunte and Rosarium Virginis Mariae cannot fail also to develop this aspect of Eucharistic worship, which prolongs and increases the fruits of our communion in the body and blood of the Lord.
The references only go back as far as Trent, but the tradition is older. This ends chapter 2.