The odd juxtaposition of beholding God in a mirror and transformation in 2 Cor 3:18 has incited many commentators to grasp for some parallel from Greek magic (R. Reitzenstein), catoptromantic ritual (H. Achelis), Dionysian mysteries (Chr. Wagner), “vision mysticism” (A. DeConick), Greco-Roman mythology (A. Weissenrieder), Wisdom traditions (M. Thrall), or Jewish hydromancy (J. Scott). All of these proposals, it is contended, fail to note the key importance of Moses in 2 Cor 3. Ancient Jewish exegetical traditions based on Num 12:6-8 portray Moses seeing God through a mirror on Mt. Sinai (Lev. Rabb 1:14; Philo, Leg. All. 3.99-101). Although most commentators note an allusion to Moses in another famous Pauline reference to a mirror (1 Cor 13:12), the allusion to the Mosaic mirror in 2 Cor 3:18 has not been explored. Using the Mosaic mirror traditions, this paper argues that Paul knew and used Mosaic mirror vision as the model for Christian catoptric seeing in 2 Cor 3:18. The Mosaic model indicates that the Christian vision through a mirror was thought of as both clear and involving a Mosaic-like metamorphosis into glory (Ex 34:29-35).