menchauser

I believe, before the time of Cyril and Methodius there were the idea that western churches shared the logic that it is possible to perform religious services only in three languages: Aramaic (Biblical Hebrew), Latin, and Greek. Cyril actually had to convince the Roman Pope that his translation of Bible to slavonic language is legit, only after that the tri-lingual restriction was considered as wrong.

Some sources could be found here: https://en.wikipedia.org/wiki/Trilingual_heresy