Introduction 21Some time between 86/705 and 99/717, Sahl b. 'Abd al-'Azīz wrote a letter to 'Uqba b. Muslim, conveying a message from the amīr al-mu'minīn, the caliph. The caliph, Sahl wrote, had announced that the time had come to make the pilgrimage, the ḥajj, and had exhorted all Muslims to do so. Sahl urged 'Uqba, if he was able, to join him on the pilgrimage and to bring Sahl's camels with him, bearing the costs for one camel himself. 2 1 I would like to thank Fred Donner and Paul Cobb who started to work on this papyrus independently and then generously shared their findings with me. I should also thank Patricia Crone, Wadad al-Kadi, Gerald Hawting and Eli Alshech for their comments on earlier drafts of this paper. The paper was first presented at the Middle Eastern Studies Association meeting in 2002, at the Institut Français d'Archéologie Orientale du Caire in 2007, and at the Institut für Alte Geschichte und Altertumskunde, Papyrologie und Epigraphik in Vienna in 2013. I would like to thank the participants of those three events for their remarks. Any errors that remain are, of course, entirely my own. 2 In this article, all dates are given as either ah/ad or simply ad, and the following abbreviations are used: Chrest.Khoury I = A. Grohmann and R. G. Khoury, ed., Chrestomathie de papyrologie arabe. Documents relatifs à la vie privé sociale et administrative dans les premiers siècles islamiques. Handbuch der Orientalistik.