Scholar and lexicographer. Born in Awāna, ca. 60 km. north of Baghdad, in the region of Ṭirhan, Bar Bahlul spent most of his life in Baghdad and belonged to the Christian intellectual elite, who interacted with Muslim scholars and were thoroughly bilingual. Bar Bahlul used both Syriac and Arabic in his publications. He was involved in the election of Cath. ʿAbdishoʿ I in 963.

Bar Bahlul’s Lexicon (Syr. Leksiqon) deals with scholarly and technical terminology and includes both Syriac words and Greek words in Syriac transliteration. The explanations are primarily in Syriac, but mostly contain equivalents and/or short comments in Arabic. Common Syriac words are normally not included. The words are taken from the Bible as well as from theological, philosophical, and scientific writings; a number of proper names are included as well. The words are in alphabetical order, even though Bar Bahlul occasionally groups together Syriac words that are based on the same root. The Lexicon brings the Syriac tradition of lexicography to full fruition. In composing it, Bar Bahlul heavily relied on two works by Ḥunayn b. Isḥāq (d. 873) — a work on homographs and a no longer extant lexicon proper (puššāq šmāhe) — as well as on a no longer extant lexicon by Ḥenanishoʿ bar Seroshway (ca. 900).

By way of these main sources and through personal reading Bar Bahlul included in his work words culled from many different authors and texts of Greek, Syriac, and Arabic origin. Some Syr. Orth. authors are occasionally quoted as well, such as Yaʿqub of Serugh, Yaʿqub of Edessa, and Mushe bar Kipho, along with a few non-Christian works, such as the Proverbs of the Arameans (matle d-Ārāmāye) — a title that reminds one of the Aḥiqar proverbs — and Kalila and Dimna. Bar Bahlul also provides rare information on dialectal variation within the Syriac language of his day, referring, among others, to the languages of Beth Aramaye, Beth Qaṭraye, Beth Garmai, Mosul (Atur), Gazarta, Edessa, and Ḥarran. Several words, expressions, names, and titles of works are known to us only through Bar Bahlul’s Lexicon, which has rightly been called a ‘linguistic and cultural encyclopedia’ (Ḥabbi). Preserved in both E.- and W.-Syr. mss., much of the information of the ‘Lexicon’ was incorporated in the modern dictionaries of R. Payne Smith and, to a lesser extent, of C. Brockelmann.

Another work by Bar Bahlul became known only a few decades ago. His ‘Book of signs’ (Kitāb al-dalāʾil), written in Arabic between 942 and 968, has the same encyclopedic breadth as the Lexicon. Probably intended as a manual for travelers, it deals with issues of calendar and, among other things, lists the festivals and commemorative days of Christians, Muslims (arranged according to the lunar months), Jews, Armenians, Copts, the people of Ḥarran, and the Sabians. Of particular importance is Bar Bahlul’s insider information on the feasts of the Ch. of E. Toward the end, the scope of this work broadens; a final section on dream interpretation has been identified as a summary rewriting of the dream manual written by the Muslim author Ibn Qutayba (d. 889).