Christian writers have often conceptualized reading and writing in terms of uncircumcision. This study begins to uncover that long-standing literary-theoretical tradition. It describes how early Christian theologians, following Saint Paul, discussed allegory with metaphors of preputiotomy, and it considers how late antique authors inflected these formulations with anatomical understandings of the prepuce. Augustine provides a remarkable example of the foreskin as both a subject of anatomical study and as a mystical heuristic for allegorical-visionary experience; and Macrobius's Commentary on the Dream of Scipio echoes anatomical writings on the prepuce in order to amplify the patristic figure into a fuller conceit. These examples lay the groundwork for imagining a poetics of the prepuce.