The Holy Canons Chalcedon Canon 13
Canon 13 Unknown clerics need letters of commendation to minister
Κανόνες τῆς ἐν Χαλκηδόνι Ἁγίας καὶ Οἰκουμενικῆς Δ´ Συνόδου
The Fourth Ecumenical Council · Chalcedon, 451 · convened by the emperor Marcian · Fourth Ecumenical Council: Chalcedon (451) on the map
Clerics who are strangers and unknown are in no way to minister anywhere in another city without letters of commendation from their own bishop.
Ξένους κληρικοὺς καὶ ἀγνώστους, ἐν ἑτέρᾳ πόλει, δίχα συστατικῶν γραμμάτων τοῦ ἰδίου ἐπισκόπου, μηδόλως μηδαμοῦ λειτουργεῖν.
The Fourth Ecumenical Council, the canons
English: this site's translation of the Greek beside it. Greek: the text of the Pedalion, as transcribed at users.uoa.gr/~nektar and corrected here. About these texts.