Правило 80
About penance for clergy and laity who missed 3 Sunday services in a row.
If a bishop, or presbyter, or deacon, or anyone of the clergy, or a layman has no urgent need or difficult matter prompting him to be absent from his church for a long time, but, remaining in the city, does not come to the congregation on three Sundays for three weeks, then if he is a cleric, let him be deposed; if he is a layman, let him be excluded from communication.
Greek original
Εἴ τις ἐπίσκοπος, ἢ πρεσβύτερος, ἢ διάκονος, ἢ τῶν ἐν τῷ κλήρῳ καταλεγομένων, ἢ λαϊκός, μηδεμίαν ἀνάγκην βαρυτέραν ἔχοι, ἢ πρᾶγμα δυσχερές, ὥστε ἐπὶ πλεῖστον ἀπολείπεσθαι τῆς αὐτοῦ ἐκκλησίας, ἀλλ᾿ ἐν πόλει διάγων, τρεῖς Κυριακὰς ἡμέρας ἐν τρισὶν ἑβδομάσι μὴ συνέρχοιτο, εἰ μὲν κληρικὸς εἴη, καθαιρείσθω· εἰ δὲ λαϊκός, ἀποκινείσθω τῆς κοινωνίας.
Parallel canons
Ап.8Трул.66Антиох.2Сард.11