Collection of biblical commentaries (OT and NT) by Severos, a monk in the Monastery of St. Barbara near Edessa , who completed his work in 861. Severos compiled his work from existing commentaries and mentions as his main sources Ephrem and Yaʿqub of Edessa (for the OT) and John Chrysostom (for the NT). Between the extracts from these works there are a number of long insertions. One of them is a full commentary on the Octateuch by Yaʿqub of Edessa (Kruisheer). In another place a long extract from the Commentary on Isaiah by Cyril of Alexandria was inserted (ter Haar Romeny, 155).

Severos’s work did not reach us in its original form, but in an expanded form, as it was written down a few decades later by the scribe Shemʿun of Ḥisn Manṣur (or Ḥesna d-Manṣur), who worked in the Monastery of the Seven Martyrs near Perrhe (Syr. Parrin). Shemʿun not only copied Severos’s work in a three-volume ms. (Vat. Syr. 103, late 9th or 10th cent., cf. S. E. and J. S.  Assemani, Bibliothecae Apostolicae Vaticanae … Catalogus, I.3 [1759], 7–28), but also — as he himself tells us (f. 371r)  — added in the margins a number of notes and comments extracted from the works of such authors as Cyril of Alexandria, Daniel of Ṣalaḥ , Hippolytus , Isidore (of Pelusium), Severus of Antioch (many extracts from his letters), Yaʿqub of Serug , and from the Book of Steps. Ms. Vat. Syr. 103, which at an unknown date was brought to Egypt, was copied in the Monastery of the Mother of God in Gazarta, near Alexandria in (what is today) ms. Brit. Libr. Add. 12,144 (Wright, Catalogue II, 908a–914a), of which the initial part (113 folios, mainly from quires 2–12) remained in Egypt (presently ms. Dayr al-Suryān Syr. 15). In this copy, the marginal comments were incorporated into the main text so that the work of Severos can no longer be distinguished from that of Shemʿun.

Ms. Vat. Syr. 103 left Dayr al-Suryān for Syria before 1646 and later came to Aleppo , where it was acquired for the Vatican Library by J. S. Assemani in 1716. Buṭros Mubārak (Petrus Benedictus) edited several parts attributed to Ephrem in his Ephrem edition (1737–1740), but in the absence of any tools for the critical study of Ephrem, he was unable to address the question of authenticity and he, therefore, sometimes uncritically combined texts of dubious authenticity with genuine Ephrem materials (such as those preserved in ms. Vat. Syr. 110). It should also be noted that some of the materials included in Severus’s collection have their counterpart in an Armenian commentary attributed to Ephrem (see Mathews).