P
ProVobis
Guest
In the 9th century supposedly. It wasn’t a language of the cross (as are Hebrew, Greek, and Latin) but it’s hard to tell if Church Slavonic was one of the languages addressed in Veterum Sapientia:My understanding is that it was constructed by SS. Cyril & Methodius, and is closest to one particular language. They also produced the written form.
Although they were sent from Constantinople, they were summoned to Rome to defend their use of this language in liturgy. Satisfied, the Pope ordained one a bishop and sent them back to their mission . . .
hawk
Venerable languages
The Church has ever held the literary evidences of this wisdom in the highest esteem. She values especially the Greek and Latin languages in which wisdom itself is cloaked, as it were, in a vesture of gold. She has likewise welcomed the use of other venerable languages, which flourished in the East. For these too have had no little influence on the progress of humanity and civilization. By their use in sacred liturgies and in versions of Holy Scripture, they have remained in force in certain regions even to the present day, bearing constant witness to the living voice of antiquity.