Its observance was extended to the Universal Church by Pope Urban IV in 1264. The office for the day was composed by St. The ceremony in which a priest or deacon removes the Sacred Host from the tabernacle and places it on the altar for adoration. In public exposition the Sacred Host is placed in the lunette of the monstrance and elevated so that all adorers can see it. In private expositions the tabernacle door is opened and the ciborium containing consecrated Hosts is brought forward.
Any good cause is reason for private adoration.
Public exposition of the Blessed Sacrament requires a period of adoration, in private or public with prescribed hymns and prayers, as well as the blessing with the monstrance. The ceremony was introduced in the fourteenth century under the influence of the newly established feast of Corpus Christi. Some religious monasteries and convents with special permission have the Sacred Host perpetually exposed for special honor and devotion with someone in attendance night and day. The solemn exposition of the Blessed Sacrament during forty hours, in honor of the forty hours the body of Christ is believed to have rested in the tomb. The devotion was introduced by St. Anthony Mary Zaccaria in Milan and Vicenza in 1527, and propagated by the Jesuits under St. Ignatius.