In the eighth century CE, the Christian theologian John Damascene referred to a Book of the Cow among the sacred texts of the Muslims. P. Hamb. Arab. 68 not only represents so far the earliest known Qurʾānic manuscript preserved on papyrus, but also bears witness to an independent circulation of the Sūra of The Cow in late seventh- or early eighth-century Egypt. Significant deviations from the commonly accepted text of the Qurʾān suggest that this copy was rapidly discarded. The present volume offers a complete edition as well as a thorough philological and historical study of the manuscript.