The Synod of Antioch in Encaeniis (341 AD)

If any bishop who has been deposed by a synod, or any presbyter or deacon who has been deposed by his bishop shall presume to execute any part of the ministry, whether it be a bishop according to his former custom, or a presbyter, or a deacon, he shall no longer have any prospect of restoration in another Synod; nor any opportunity of making his defence; but they who communicate with him shall all be cast out of the Church, and particularly if they have presumed to communicate with the persons aforementioned, knowing the sentence pronounced against them.

Ancient Epitome of Canon IV.

If a bishop deposed by a synod shall dare to celebrate the liturgy, let him have no chance of return.

This canon derives its chief interest from the fact that it is usually considered to have been adopted at the instigation of the party opposed to St. Athanasius and that afterwards it was used against St. Chrysostom. But while such may have been the secret reason why some voted for it and others prized it, it must be remembered that its provision is identical with that of the Apostolic Canons, and that it was read at the Council of Chalcedon as Canon eighty-three. Remi Ceillier tries to prove that this is not the canon which St. Chrysostom and his friends rejected, but Hefele thinks his position “altogether untenable”, and refers to Tillemont (Mémoires, p. 329, Sur les Arians, and Fuchs’ Bib. der Kirchenversammlungen, P. II., p. 59.)

Compare Apostolic Canon xxviij.

This canon is found twice in the Juris Corpus Canonici, Gratian’s Decretum, Pars II., Causa XI., Quæst. III., Can. vj., and Can. vij. in the version of Martin Bracarensis. This version is very interesting as expanding the phrase “to execute any part of the ministry” into “to make the oblation, or to perform the morning or evening sacrifice as though he were in office just as before, etc.”