The focus of this report is the still-unexplored Interpretation of Orthodox
liturgy, attested in two copies: first in manuscript No. 88 from the collection of Obolensky
(201), State Archive of Russian Federation (Moscow), the second in manuscript No 52
of 1567, from the Archive of Baltazar Bogisić in Cavtat. The two manuscripts contain
proven original works of Constantine of Kostenets (1380–1431). The author analyzes
the structure and content of the interpretation and comments on it as a source for the
history of Liturgy – from the point of view of the data concerning the liturgical features
described in it. It can be concluded that the basis of texts in MS No 88 and MS Bogishić
52 is a late composition of Byzantine mystagogy, which, in turn, means that the time of
implementation of the South Slavic translation should be dated no earlier than the end
of the 12th century. This is one of the many short epitomes created during the Second
Bulgarian Kingdom as a result of the secondary reduction of the original extensive
commentary. A detailed investigation and the text-critical edition will be forthcoming.