The monograph presented here to students of Arabic and Islam is dedicated to the most significant document that has survived from the time of the Prophet Muhammad, namely the so-called “Constitution of Medina”. Al- though the original document was not preserved and is only known from literary sources, it is widely acknowledged as authentic and as dating back to the time of the Prophet. Given its importance and wide acceptance it is surprising that so little scholarly effort has so far gone into the interpreta- tion of the document, which is replete with difficult words and expressions. It was felt that any progress achieved in the study of this document would enrich the resources available for the study of early Islam. Like a first love, one always returns to one's doctoral thesis. Most of the research behind this study was carried out some two decades ago when I was writing my Ph.D. thesis at the Hebrew University of Jerusalem under the close supervision of M.J. Kister. At that time the evidence supporting the emendation umma/amana (§28) did not seem to be convincing, which is probably the reason why my findings have taken so long to appear. Meanwhile new evidence has emerged that in my opinion supports this emendation.

Fortunately for me, research on my Ph.D. thesis coincided with the convening of an international workshop in Jerusalem, followed by the first in a series of colloquia entitled “From Jāhiliyya to Islam”. As early as in October 1979 the interpretation of the said umma/amana clause was the topic of my very first scholarly lecture. I recall G.H.A. Juynboll's warm welcome of my argument (as well as his discreet correction of a glaring error in Arabic). At a colloquium on ḥadīth convened in Cambridge in 1985 by the late Martin Hinds and Patricia Crone I presented a paper entitled “On the Participation of the Main Jewish Clans in the Document Known as ‘The Constitution of Medina'”. An extended version of its first part is now published. An early draft of the paper was read in 1980 by Michael Zwettler, who was among the workshop participants; I am indebted to him for his valuable comments. Excursus C (“The Recensions of the Kitāb“) was presented in 1988 at the ḥadīth colloquium convened in Oxford by the late Martin Hinds, Patricia Crone and G.H.A. Juynboll. It is my pleasant duty to thank the organizers and participants for their helpful comments.