Gregory the Great (ca. 540-604 AD), Moralia sive Expositio in Job [Morals or Exposition on the Book of Job] (ca. 591 AD)
Members of the English Church (trans.), Morals on the Book of Job by Gregory the Great, the First Pope of That Name, 3 vols. (A Library of Fathers of the Holy Catholic Church Anterior to the Division of the East and West), Oxford: Parker, 1844-1845, 1847. Read at archive.org.