Second Council of Nicaea, Canon XIII

That they are worthy of special condemnation who turn the monasteries into public houses.

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.”

Translation: Henry R. Percival, The Seven Ecumenical Councils, NPNF II.14 (1900), via CCEL.