The Second Council of Nicaea (787 AD)

That to churches consecrated without any deposit of the reliques of the Saints, the defect should be made good.

Paul the divine Apostle says: “The sins of some are open beforehand, and some they follow after.” These are their primary sins, and other sins follow these. Accordingly upon the heels of the heresy of the traducers of the Christians, there followed close other ungodliness. For as they took out of the churches the presence of the venerable images, so likewise they cast aside other customs which we must now revive and maintain in accordance with the written and unwritten law. We decree therefore that relics shall be placed with the accustomed service in as many of the sacred temples as have been consecrated without the relics of the Martyrs. And if any bishop from this time forward is found consecrating a temple without holy relics, he shall be deposed, as a transgressor of the ecclesiastical traditions.

Ancient Epitome of Canon VII.

Let reliques of the Holy Martyrs be placed in such churches as have been consecrated without them, and this with the accustomed prayers. But whoever shall consecrate a church without these shall be deposed as a transgressor of the traditions of the Church.

But someone may be surprised that oratories to-day are consecrated without any deposition of reliques. And they may ask why the Divine Liturgy is not celebrated in them by bishops and not by priests only. The answer is that the superaltars (ἀντιμένσια) which are made by the bishops when a church is consecrated, suffice oratories in lieu of consecration or enthronement when they are sent to them, on the occasion of their dedication or opening. They are called ἀντιμένσια because they are in place of, and are antitypes of those many like tables which furnish thoroughly the holy Lord’s table.

On the rite of consecrating churches with reliques see Cardinal Bona.

The Antimensia are consecrated at the same time as the church; a full account of the ceremony is found in the Euchologion (Goar’s ed., p. 648). A piece of cloth is placed on the altar and blessed, and then subsequently, as need requires, pieces are cut off from it and sent to the various oratories, etc. The main outline of the ceremony of consecration is as follows.

J. M. Neale.

Relics being pounded up with fragrant gum, oil is poured over them by the bishop, and, distilling out to the corporals, is supposed to convey to them the mysterious virtues of the relics themselves. The holy Eucharist must then be celebrated on them for seven days, after which they are sent forth as they are wanted.