This book marks an auspicious beginning for Harvard's series in Islamic Law. Jewish and Islamic Law breaks new ground on several fronts and points the way toward important lines of research in comparative study of religious law...[Libson's] attention to methodology, social context and detailed examples assures that his book will remain an essential resource for many years to come.

Jewish-Islamic comparative law is a relatively underdeveloped field...What few studies there are have tended to restrict themselves to determining Jewish antecedents for Islam, and even those normally focus on ritual, not law. Libson's study of the use of custom by the geonim and its connection to Islamic law is a novel and welcome corrective. This excellent study shows that the relationship between Jewish law and the Islamic law is much more complex than is normally assumed. Libson's familiarity with the ancient texts and current scholarship of both Jewish law and Islamic law is truly remarkable.

This remarkable collection of studies is a pioneering contribution to the study of Jewish and Islamic law in the period, and it is hard to imagine serious future work in these fields that will not refer to this volume.