Liturgy of the Presanctified Gifts
The Liturgy is used by the Eastern Orthodox Church and those Eastern Catholic Churches that follow the Byzantine Rite. Great Lent is a season of repentance, fasting, and intensified prayer, and so the Eastern Church regards more frequent reception of communion as especially desirable at that time. However, the full Divine Liturgy has a joyful character not in keeping with the somberness of the season of repentance (Eucharist literally means "thanksgiving"). The Presanctified Liturgy is therefore celebrated instead. Although it is possible to celebrate this service on any weekday (Monday through Friday) of Great Lent, common parish practice is to celebrate it only on Wednesdays, Fridays and those feast days which fall on a weekday. It is also called for by the Typicon on Monday, Tuesday and Wednesday of Holy Week.
The Liturgy consists of vespers combined with additional prayers and communion. Vespers is followed as normal through the Little Entrance, after which certain hymns and litanies are chanted, and silent prayers are said by the priest, some of which are unique to the Presanctified Liturgy, and some of which parallel those of the normal Divine Liturgy.
On the previous Sunday, additional Lambs (Hosts) are prepared and consecrated, enough for all of the Presanctified Liturgies that will be celebrated in the coming week. The exact same ceremonies and actions accompany the preparation and consecration of the extra lambs, as the one which will be used that day at the Divine Liturgy. After the consecration, just before the communion of the clergy, the rubric calls for the consecrated Lamb to be intincted with the consecrated Blood of Christ; however, depending on local practice, this is sometimes not done. In either case, the consecrated Lambs are reserved, often in a special pyx used only for this purpose.
Then, on the day of the Presanctified Liturgy, during the Kathisma (reading from the Psalter), one of the consecrated Lambs is placed on the diskos (paten) and unconsecrated wine is poured into the chalice. These are then censed and covered with veils. The Great Entrance takes place in a manner similar to that of the Divine Liturgy, except that the priest rather than the deacon carries the diskos, he holds it higher than the chalice, and the entrance is made in absolute silence, while everyone makes a full prostration.
When it comes time for Holy Communion, the clergy make their communion as normal, except that no words accompany their drinking from the chalice. Those portions of the reserved Lamb which will be used to give communion to the faithful are placed in unconsecrated wine in the chalice. Local practice varies as to whether or not this unconsecrated wine must be thought of as the Blood of Christ (even if the bread was intincted). The only practical effect of this variety is that the celebrant (priest or deacon) who must consume all the undistrubuted communion at the end of the service might or might not partake of the chalice when he communes himself: if the wine that was poured into the chalice is not the Blood of Christ, he would need to consume all of the consecrated elements before drinking any of the wine because drinking unconsecrated wine breaks the Eucharistic fast.
The Liturgy of the Presanctified Gifts was first documented by Gregory Dialogos (540–604), who had been the papal legate to Constantinople. At one time it was supposed that he had composed the Liturgy himself, but now it is generally supposed that he simply recorded what was otherwise being practiced at Constantinople. In the Presanctified Liturgy itself, he is still commemorated as its traditional author.
On all days of the holy fast of Lent, except on the Sabbath [i.e., Saturday], the Lord's Day [Sunday], and the holy day of the Annunciation, the Liturgy of the Presanctified is to be served (Canon 52).
Other liturgical traditions 
Thus, for instance, there is a similar penitential rite used by the Roman Catholic Church on Good Friday, officially called the rite of Commemoration of the Lord's Passion, but informally known, especially among Catholics who celebrate the Liturgy in accordance with the Tridentine discipline, as Mass of the Presanctified. Because there is no consecration of the gifts in that Liturgy, it is not technically a Mass; rather, it is a reception of Holy Communion from the reserved Sacrament which was consecrated at Mass on Holy Thursday.
In the Anglican Communion, the Book of Common Prayer for the United States provides for the consecration of the Reserved Sacrament on Maundy Thursday and its reception at the special liturgy of Good Friday.
The Liturgy of the Presanctified Gifts was once used in the West Syrian Rite, the liturgy of the Syriac Orthodox Church, but has fallen into disuse in most of the Syriac Orthodox communion. However, it continues to be used in the Malankara Rite, a variant historically practiced in the Malankara Church of India, and now practiced by the several churches that descended from it.
See also 
- The Liturgy of the Presanctified Gifts
- Chupungco, p. 17.
- Chupungco, Anscar J. (1997). Handbook for Liturgical Studies. Liturgical Press. ISBN 0-8146-6161-0. Retrieved April 5, 2010.