His work on the Pauline epistles included proposed revisions to many accepted attributions, notably of Ambrosiaster, as well as numerous commentaries on and editions of other works.
The commentary itself was written during the papacy of Pope Damasus I, that is, between 366 and 384, and is considered an important document of the Latin text of Paul before the Vulgate of Jerome, and of the interpretation of Paul prior to Augustine of Hippo.
It consists of five manuscript folios, contains quotes from the Vulgate and Vetus Latina Bible; patristic commentary by Augustine, Jerome, Cyprian, Origen, Ambrosiaster and Gregory the Great; extracts from Canon law, ecclesiastical history and synodal decrees from Nicea and Arles in their original, uncontaminated forms, in addition to a decretum that enjoined on the Irish that, if all else failed, they should take their problems to Rome.
1 Cor. 15:3 – ο και παρελαβον (I received), omitted by b, Ambrosiaster, Irenaeuslat, Tertullian?