Exposition Began?

The custom for taking communion home to be eaten during the week is attested to by second and third century writers [Tertullian, Hypolitus] and into the late fourth century [Jerome and Basil of Caesarea +379]. From this custom developed the practice of celebrating the Eucharist on certain weekdays as well. These days were attached to the martyr and their "sacrifices" for the faith. Eucharist became part of Christian burial.

By the 4th century, a custom of showing or lifting the Eucharistic element began to develop. St. Euverte, a bishop of Orleans, documents this practice. Along side this development Theodore of Mopsuestia and others are "allegorizing" the liturgy, making references to each part of the eucharist and the drama of Christ's life. With this shift from symbol of the eucharist to metaphor, from eucharist as action to object, the cult of adoration of the blessed sacrament begins. The eucharist becomes something not only to be blessed and consumed, but also adored and reverenced. Tabernacles began to develop in very simple forms, such as cupboards or in churches, hanging doves. Due to the allegorical nature of the age, they are reminiscent of tombs.

From these simple boxes it was a long progression until the 12th, or more likely, 13th century when the evidence of monstrances appeared. Because of the growing popularity of processions of the blessed sacrament, the eucharist needed to be viewed in a proper vessel of reverence and exposition. For an excellent overview of this history of eucharist, see Nathan Mitchell's "Cult & Controversy," published by Pueblo Books, Collegeville, MN, 1982.