Safinaye Tabriz is a major Persian Encyclopedic text from the 13th century Ilkhanid era. Its compiler was a scholar from Tabriz who collected important works in Persian and Arabic and consolidated portions from important texts in one manuscript. This manuscript, which is the Safinaye Tabriz has also important linguistc value. A good amount of poems and writings in Fahlaviyyat are mentioned in this work. Here is an article by Dr. Sadeqi which discuses the Tabrizi and Karaji Iranic dialects (see Old Azari Iranian language before Turkicization of Azerbaijan) from this manuscript. It should be noted the author of the Safinaye Tabriz himself from Tabriz calls this the Tabrizi dialect and this gives a first hand account of this important but now dead Iranian Tabrizi language of Tabriz in the 13th century.