Peter Comestor's oral lectures on the Glossa ordinaria were originally delivered at the cathedral school of Paris around the year 1160 and survive in the form of student transcripts. As one of the period's pioneering masters, Comestor lectured using the newly-fashioned biblical Gloss as his textbook, meticulously weaving its component glosses into his teaching to distil its richly varied patristic exegesis. While at times elegant and consciously rhetorical, Comestor's lectures are preserved in vividly conversational Latin, bearing traces of the master's direct address to his students and lively examples drawn from contemporary life in the schools. Edited for the first time from the late twelfth-century manuscript Troyes, Mediatheque du Grand Troyes, MS 1024, the prefatory material of Comestor's lecture courses on the four glossed Gospels offers a unique glimpse into the classroom of one of Paris's preeminent masters at the height of the renaissance of the twelfth century.