I have minimal familiarity with the Eastern Orthodox tradition, but I can typically guess by seeing a photo that a person is an Eastern Orthodox clergyman.
Is there any theological reason that Eastern Orthodox clergy tend to maintain long beards?
It's a tradition derived from two sources: first of all, Jesus had long beard - second, from Leviticus 19:27 "You shall not round off the hair on your temples or mar the edges of your beard"
However, it's not a prescription for ortodox clergy to do that: it's only a (widely observed) tradition Note that catholic clergy usually not maintain long beards, for a different tradition: Romans used to shave their beards, and to consider men with long beards as uncivilized (barbarians). Anyway, there is no prescription about beards (exept for some monks)
Ion Creanga was defrocked for shaving his beard; not only was it a requirement for clergy, it was a requirement for all grownup males; Old Believers are notorious in this respect; the social reforms of Peter the Great caused quite a stir among the Russian nobility, who, after being forced, under threat of punishment, to shave their faces, so as to better resemble their Western counterparts, kept their cut hair, so as to present it to Saint Nicholas on judgment day.– user46876Nov 12, 2021 at 2:42