During the calamity which was brought to pass in the Churches, because of our sins, some of the sacred houses, for example, bishops' palaces and monasteries, were seized by certain men and became public inns. If those who now hold them choose to give them back, so that they may be restored to their original use, well and good; but if not, and these persons are on the sacerdotal list, we command that they be deposed; if they be monks or laymen, that they be excommunicated, as those who have been condemned from the Father, and the Son, and the Holy Ghost, and assigned their place where the worm dieth not and the fire is not quenched, because they set themselves against the voice of the Lord, which says: "Make not my Father's house an house of merchandise."
Ancient Epitome of Canon XIII.
Those who make common diocesan or monastic goods, unless they restore to the bishop or superior the things belonging to the diocese or monastery, the whole proceeding shall be null. If they are persons in Holy Orders they shall be deposed, but if laymen or monks they shall be cast out.
No doubt by "the calamity" here is intended a reference to the troubles occasioned by the Iconoclasts, during whose time of domination many nefarious things were perpetrated against the orthodox, and most bitter of all was the persecution of the monks and priests by Leo the Isaurian and by his son Constantine Copronymus, both of them supporters of the Iconoclasts.
And so it came to pass that by this persecution and through the nefarious vexations of the Iconoclasts, many monks and clerics fled from their monasteries and left vacant the Episcopia or holy houses, and so it became easy for people to come in and occupy the empty monasteries and religious houses, and to turn them to common and profane uses, especially when the anger of the Emperors and of the Iconoclasts was known to be fierce against the monks, and such bishops and priests as were worshippers of images.
This canon is found in the Corpus Juris Canonici, Pars. II., Causa xix., Quæst. III., canon v., in Anastasius's version but lacking the opening words which are supplied by the Roman Correctors.