Isho'dad of Merw, Bishop of the East Syrian Church in Hedatta, wrote hiscommentaries on the books of the Old and New Testament around 850 A.D.His work constitutes one of the most important and extensive exegeticalcollections within the East Syrian Church. From 1911 to 1916 Margaret D.Gibson published a text edition and an English translation of the NewTestament Part. Developments in the area of manuscript tradition, thediscovery of new sources and the many deficiencies in Gibson's work,made a new text edition and translation necessary. The starting pointhas been taken in Isho'dad's commentary on the Gospel of St. John. Thisgave the opportunity to trace in Isho'dad's commentary the influences ofthe work of Theodore of Mopsuestia, whose commentary on the Gospel ofSt. John has survived in the Syriac language. Volume 671 (Textus)offers a Syriac text edition based on 15 manuscripts. In theIntroduction these manuscripts and their mutual relationship aredescribed. Volume 672 (Versio) contains a description ofIsho'dad's life, a study of the sources used by him, and a translation.The volumes include a survey of Gibson's errata, an orthographical indexand an index of biblical citations and Greek terms quoted.