At this stage it is necessary to notice the fresh invasion of Syria by Hadad (Adad)-nirari, who besieged Mari, king of Damascus, and exacted a heavy tribute (c. Boo B.C.).
Within a few miles are the thermal springs of Olanestzi and the salt mines of Ocnele Mari.
To the Nestorian movement in Persia he rendered useful service by his letter to Mari of Beth Hardasher, in which he maintained the tenets of Diodore and Theodore, while allowing that Nestorius had erred.
The descendant of men learned in rabbinic lore, Abba Mari devoted himself to the study of theology and philosophy, and made himself acquainted with the writing of Moses Maimonides and Nachmanides as well as with the Talmud.
The "Holy Leaven" is reputed to be a part of the original bread of the first Eucharist, brought by Addai and Mari' and maintained ever since in the Church; it is used in the confection of the Eucharistic wafers, which are rather thicker than those used in the Western Church.