Liber Extra
While ecclesiastical ownership was going through these phases, the canon law decided who must contribute to the maintenance of a particular church, i.e. its owner, and all recipients of its revenues (Synod of Frankfort, 794); under pain, therefore, of forfeiting his right of patronage, the patron of a church must share the burden of its maintenance; so too the incumbent of the ecclesiastical benefice and those to whom the tithes have been granted (). Finally, when the resources of the church were insufficient, the faithful themselves were bound to contribute to the expenses of Divine worship. These provisions were sanctioned by the Decretals of Gregory IX (cc. i and iv de ecclesiis ædificandis, III, 48), and by the Council of Trent (Sess. XXI, de ref. c. vii); they represent in this matter the common ecclesiastical law.