Once considered the “primordial source of all books” and a proxy for the Qurʾān itself, the Persian and Bengali versions of the Nūrnāma (Book of Light) virtually disappeared from the religious landscape of contemporary Bangladesh and West Bengal. The Book of Light narrates the creation of the world by God through the body of the Muḥammad of light. This creation story played a key role in shaping the popular understanding of Islamic cosmology, language, and the significance of the written word in Bengali Islam. With this lecture, I will address the topic of vernacular literacy and multilingualism in Bengal between the 17th and 19th century through the study of the Nūrnāma tradition. A fresh look at the textual tradition that surrounded the transmission of this creation story reveals ways to conceive of vernacular Islam beyond categories of elite vs. popular, or orthodox vs. heterodox.