Composed in about the year 725, the Liber Questionum in Euangeliis (LQE) is a comprehensive reference commentary on Matthew intended for ecclesiastics in the writing, teaching, and preaching professions. Its anonymous Irish redactor gathered together all the relevant patristic and native material available, adding to and adapting much of a still largely unpublished commentary on Matthew by the Hiberno-Latin writer Frigulus (fl. ca. 700). LQE's well-attested manuscript tradition and its far-flung exegetical influence make it one of the more intriguing texts to appear in the Scriptores Celtigenae series. Although LQE's origins are in Ireland (and one Irish fragment still survives), its manuscript families also include witnesses from England and the Continent. Not only is LQE a typical product of the early Irish church, but its considerable length, the variety of its sources, and its influence on later writers further reveal the work to be central to the entire early medieval Gospel commentary tradition. In addition to exegetes in England, the Carolingian writers Haimo of Auxerre (ob. 853), Rhabanus Maurus of Fulda (780-865), and especially Paschasius Radbertus of Corbie (ob. ca. 865) adapted it for their own works on Matthew. Rittmueller's painstakingly researched edition and introduction will serve as an invaluable resource in early medieval Biblical studies for decades to come.