This dissertation studies a heretofore neglected Carolingian biblical commentary on Deuteronomy preserved in Paris, Bibliothèque nationale de France, NAL 1740. Paris, BnF, NAL 1740 is a Bible codex from early medieval Lyon. In the early ninth century, a scribe of Lyon cathedral copied more than 400 exegetical annotations alongside the Deuteronomic verses, either in page margins or between the two columns of the main text. Although Paul-Irénée Fransen provided a modern edition of the biblical commentary constructed by these annotations ("the Lyon Annotations" as I designate it), there has been no in-depth study of them. This dissertation argues that this commentary was composed during the first two decades of the ninth century by a master active in the cathedral school of Lyon, then copied down by the episcopal scriptorium to create a commented Bible codex. While both its general scheme and part of its concrete expositions are rooted in the Latin exegetical tradition of Deuteronomy that accumulated and evolved from Origen to the second half of the eighth century, it shows a high level of originality not commonly associated with the biblical exegesis of the Carolingian era. Its author creatively presents a Christian community self-identified as the "spiritual Israel" and the Jewish people as the "carnal Israel" as its theological antithesis. This dissertation also demonstrates that the Lyon Annotations was the product of the church reform initiated by Archbishop Leidrad whom Charlemagne appointed in 798 to ameliorate the condition of the Lyon church. The intellectual life revived by Leidrad's reform project provided conditions for the making of this unique exegetical treatise. In turn, the Lyon Annotations served Leidrad's goal of creating a well-educated team of elite clergy.