most of it; and that register is the most important of the Muslims’ registers. The provincial centres also had registers for land tax, fay’, and other revenues collected. The Prophet, peace and blessings be upon him, and his successors would audit their officials’ accounts of obligatory alms, fay’, and other funds.

Thus, in this period and earlier, revenues came to fall into three categories:

One category consists of funds that the ruler is entitled to collect according to the Quran, the Sunnah, and scholarly consensus, as we have mentioned. Another consists of funds whose collection is unanimously prohibited, such as levies collected from villagers for the public treasury because someone has been killed among them—even when the deceased has an heir—or payments exacted for an offense someone has committed that incurs a prescribed punishment, which is then waived in return. This also includes tolls whose imposition is unanimously held to be unlawful. A third category is subject to juristic judgment and disagreement, such as the estate of someone who has a blood relative who is neither a fixed-share heir nor a residuary heir, and similar cases.

Rulers and subjects frequently wrong one another in these matters: the former take what is unlawful, while the latter withhold what they are obliged to pay, just as soldiers and farmers may wrong one another. Likewise, some people neglect their obligations of striving in Allah’s cause, while rulers hoard wealth belonging to Allah that they are not permitted to hoard. The same applies to punishments used to enforce payment: punishments that are permissible or obligatory may be neglected, while unlawful punishments may be inflicted.

The underlying principle is that anyone obliged to hand over money or property—such as a man