Abstract
: A rich array of twelfth to fifteenth century Arabic texts captures the advent of a supererogatory prayer known as ṣalāt al-raghā’ib, on the eve of the first Friday of the month of Rajab in late eleventh-century Jerusalem, and its wide dissemination. This corpus offers an unusually vivid picture of the formation and the transformation of a medieval bid’a, or, of an ‘invention of tradition’. Combining our expertise in Islamic law and in Ayyūbid and Mamluk era history, we use this corpus for an in-depth study of popular piety, power politics, scholarly polemics and legal discourse. Twenty eight translated excerpts of various texts are presented in this paper, preceded by a detailed introduction. Exploring legal reasoning in its concrete political and social context provides a nuanced understanding of the development, mass proliferation and ensuing debate over a highly controversial and extraordinary potent religious practice.