Dictionary of Christian Biography and Literature to the End of the Sixth Century/Thomas Edessenus
Thomas (8) Edessenus appears in the Life of Mar Abas. The latter, originally Magian by religion, was converted to Christianity, learnt Syriac at Nisibis, and Greek at Edessa from Thomas a Jacobite, whom he afterwards took with him to Alexandria and there with his help translated the Scriptures (or, the books) from Greek into Syriac (Gregory Bar-hebr. Chr. Eccl. ii. 22, t. iii. col. 189). Amrus (ap. Assem. iii. 75) gives a similar history of their relations; but only ascribes to them the translation of the works of Theodore of Mopsuestia. He relates how they went to Constantinople, and finding their lives in peril in consequence of their refusal to "anathematize the Three Fathers," fled to Nisibis. There Mar Abas became a teacher, and an eloquent assailant of Zoroastrianism. Gregory says that he was at one time taught by John Grammaticus, the Tritheite; but the facts alleged by Amrus lead us to conclude that he lapsed early into Nestorianism. He was elected catholicus of the Chaldeans in 536, and persecuted by the Magians. Chosroes called on him to return to his original faith or to conform to Christian orthodoxy. Refusing to do either, he was exiled, and venturing to return to his see without the king's permission, was cast into prison, and died there, 552. Among his disciples Amrus (Assem. ii. 411) reckons "Thomas of Edessa," no doubt his former teacher drawn by him from the opposing sect into Nestorianism. Of their joint work, the version of Theodore's liturgy survives (Brit. Mus. 7181, Rich., R.-F. Catal. p. 59—see also Rénaudot, Liturg. Or. t. i. p. 616); and the liturgy of Nestorius (ib. p. 626), still in use in the Nestorian churches, is probably their version mentioned by Ebedjesu (Catal. Assem. iii. 36), who also says they translated the O.T. (ib. 75), and adds a list of the writings of Mar Abas.