Правило 83
About the ejection of clerics combining priestly and military service.
A bishop, presbyter or deacon who is in military service and wants to retain both - the Roman authorities and the priestly ministry - let him be deposed, for the things that are Caesar's are to Caesar, and the things that are God's to God.
Greek original
Ἐπίσκοπος, ἢ πρεσβύτερος, ἢ διάκονος, στρατείᾳ σχολάζων καὶ βουλόμενος ἀμφότερα κατέχειν, Ῥωμαϊκὴν ἀρχὴν καὶ ἱερατικὴν διοίκησιν, καθαιρείσθω. Τὰ γὰρ Καίσαρος, Καίσαρι· καὶ τὰ τοῦ Θεοῦ, τῷ Θεῷ.
Parallel canons
Ап.681IVВс.3VIIВс.10Карф.16Двукр.11Вас.55