Bar-ṢalĪbĪ, JACOB or DIONYSIUS, the best-known and most voluminous writer in the Syrian Jacobite church of the 12th century, was, like Bar-Hebraeus, a native of Malatia on the Upper Euphrates. In 1154 he was created bishop of Mar‛ash by the patriarch Athanasius VIII.; a year later the diocese of Mabbōg was added to his charge. In 1166 Michael I., the successor of Athanasius, transferred him to the metropolitan see of Āmid in Mesopotamia, and there he remained till his death in 1171. A long account of his writings, with copious extracts from some of them, has been given by Assemani (Bibl. Orient. ii. pp. 156-211); and W. Wright (Syriac Literature, pp. 246-250) has added further particulars as to the MSS. in which they are contained. Probably the most important are his exhaustive commentaries on the text of the Old and New Testaments, in which he has skilfully interwoven and summarized the interpretations of previous writers such as Ephrem, Chrysostom, Cyril, Moses Bar-Kēphā and John of Dārā, whom he mentions together in the preface to his commentary on St Matthew. Among his other main works are a treatise against heretics, containing inter alia a polemic against the Jews and the Mahommedans; liturgical treatises, epistles and homilies.
His commentaries on the Gospels were to some extent used by Dudley Loftus in the 17th century. But the systematic editing of his works was only begun in 1903 with H. Labourt's edition and translation of his Exposition of the Liturgy (Paris). His commentaries on the Gospels have been edited and translated by J. Sedlaček and J. B. Chabot (Fasc. I., Paris, 1906), and the Syriac text of the treatise against the Jews has been edited by J. de Zwaan (Leiden, 1906). Bar-Ṣalībī was undoubtedly an able theologian; his vigour combined with terseness in argument is well seen, for instance, in the introductory sections of his commentary on St Matthew. Of his originality it is hard to judge, as he does not usually indicate in detail the sources of his arguments and interpretations. He does not, however, claim for himself to be more than a compiler, at least in his commentaries. His Syriac style is good, considering the lateness of the period at which he wrote.
 Jacob was his baptismal name; Dionysius he assumed when consecrated to the bishopric.