Kitab al-Amwal (The Book of Revenue) is the work of a brilliant legal mind. Abu Ubayd al-Qasim ibn Sallam provides us with an accurate record of legal precedents laid down in the first two centuries of Islam, in particular those pertaining to the sources of revenue and the avenues of public expenditure. The power of the book, however, lies in the method of the author and the analysis undertaken by him. He gathers together the traditions of the Prophet (pbuh), the opinions of his companions and the views of eminent jurists, and then subjects them to legal analysis that is unparalleled in...