 In 666–667, he translated nine treatises of the "Hexameron" of Basil of Caesarea, as suggested by Matthew, Bishop of Aleppo, and Daniel, Bishop of Edessa.Matthew and Daniel later requested a translation of several letters of Severus of Antioch into Syriac which was complete in 669, under the pen-name of "Athanasius of Nisibis".Athanasius also translated Severus' "Second Discourse against Nephalius", several homilies by Gregory of Nazianzus, and the "Corpus Areopagiticum" by Pseudo-Dionysius the Areopagite.