Letter 1.24 to Bishop John of Constantinople, Bishop Eulogius of Alexandria, Bishop Gregory of Antioch, Bishop John of Jerusalem, and Anastasius, ex-patriarch of Antioch (February 591)
In this lengthy letter, Gregory discusses how the priests should behave and in what way they should differ from the laymen. He also explains the metaphorical meaning of the priestly haircut. Since the priests described by Gregory have the highest authority among the faithful, he seems to refer particularly to bishops. Curiously, however, Gregory never uses the word bishop or its derivatives (such as episcopatus), which he otherwise employs frequently in his writings. Instead, Gregory addresses the priest as antistes, rector, and sacerdos.
(ed. Norberg 1982: 22-32, summarised by J. Szafranowski)