The comparative analysis of the manuscript sources allows us to outline the general path of development of manuscript number 3917 kept in the Matenadaran after M. Mashtots; it contains the “Interpretation of Grammar” by Grigor Magistros (990–1058) and presents the scientific and educational environment in which this grammatical work was spread. As a result of the research, it becomes clear, that the “Interpretation” by Magistros was used in Tatev and Sarkavagants Monasteries. In the 15th century, when the interpretations of Hovhannes Yerznkatsi, Hovhannes Tsortsoretsi, and Vardan Areveltsi were created, Grigor Tatevatsi handed over the original of the “Grammar” by Magistros to his student Archimandrite Hovhannes Karmir from Kapan to circulate in the Sarkavagants Monastery.

KeywordsGrigor Magistros “Interpretation of Grammar” manuscript colophon Grigor Tatevatsi Archimandrite Hovhannes Tatev Monastery Deacon Monastery library writing center.