the abbasìd’s golden age 207Kharàj do not have. First, it does not focus on one type of wealth;
rather it incorporates all types that may be generated from agricul-
ture, trade, or other sources. For example, in contrast to previous
work, it looks into the wealth generated from trade, as well as agri-
culture, and the rules regarding the tax imposed on it. In that sense
it is more comprehensive in providing a blend of macro and micro
economics than previous works.
Second, it is much better documented than any of the others. Not
only do we see clearly isnad, the citation of a chain of informants
of the Prophet’s sayings and deeds, but also we read letters sent by
the Prophet and caliphs after him to their officials and leaders of
their adversaries, and examine the treaties between Muslims and
non-Muslims—all well documented. In that sense, Abù-Ubaid spent
more time to provide documented proof of what was practiced in
the past and, presumably, ought to be practiced at his time. One
would not suggest that the writers of previous works were not aware
of these documents, but Abù-Ubaid is given the credit for incorpo-
rating them in one volume presented in a well documented form.
The focus of each writer is, however, equally appreciated.
Third, the book provides a greater variety of opinions on the
treated subject. This was perhaps made possible by the fact that
Abù-Ubaid’s writing came much later than that of the others, prob-
ably between thirty and forty years after Abù-Yùsuf ’s. During that
period a wider variation of opinion would have been developed,
enhanced, by the further variation in the juridical schools of thought.
A further feature could perhaps be added to the above three.
Although the book can serve the purpose of the state in shaping its
finance, it can also be useful to the reader in general. It shows
Muslims and non-Muslims their duties, rights and commitments with
regard to both what is levied on them as financial right of the state,
which they need to follow as good citizens, and what is imposed on
them by the divine right, that they need to observe as pious Muslims.
Further, for lawyers, advocates, or those defending their case, the
book is a valuable legal text that provides rules and case law in a
manner that helps reinforce the submission for and against.
Abù-Ubaid’s Kitàb al-Amwàl is a manual in public finance. Details
of practice are well explained, as well as being well documented, in
a manner that would serve officials in dealing with what ought to
and ought not to be taxed, who should and should not be taxed,
the factors that justify the imposition of taxation, and how revenues