Canon 9
On the inadmissibility of the faithful to leave the Liturgy without participating in prayer and communion.
All those faithful who enter the church and listen to the Scriptures, but do not remain at prayer and during holy communion, should be excommunicated as disturbing the order in the church.
Greek original
Πάντας τοὺς εἰσιόντας πιστούς, καὶ τῶν γραφῶν ἀκούοντας, μὴ παραμένοντας δὲ τῇ προσευχῇ καὶ τῇ ἁγίᾳ μεταλήψει, ὡς ἀταξίαν ἐμποιοῦντας τῇ ἐκκλησίᾳ ἀφορίζεσθαι χρή.
Parallel canons
Трул.6680Антиох.2Сард.11