If the amount varied according to the types of merchandise and property, the different rates were to be itemized in the register. The dīwān was established to record the applicable dues and collect what was owed according to the quantities of merchandise brought into its jurisdiction.

As for the ʿushr levied on property transported within the Abode of Islam from one town to another, it is forbidden. No provision of the Sharīʿah permits it, independent legal reasoning cannot justify it, and it is not among the policies of justice. It is found almost exclusively in lands ruled unjustly. For this reason, the Messenger of Allah ﷺ said: “The one who levies an unlawful toll will not enter Paradise.” In another wording: “The one who levies an unlawful toll is in the Fire”—that is, the collector of the tenth. Another wording states: “When you encounter a collector of the tenth, kill him.” Abū ʿUbayd narrated these reports in his Kitāb al-Amwāl.

If the governors alter the laws governing the lands and the amounts of the dues owed therein, what they have done must be examined. If their action is justified by independent legal reasoning on account of a matter that necessitated it—one that the Sharīʿah does not prohibit—because a cause has arisen for which the Sharīʿah permits an increase or decrease, then it is permissible. The second assessment becomes the rightful due to be collected, rather than the first. When the assessment in force is taken from the dīwān, it is permissible to record only the second assessment and omit the first. It is more prudent, however, to record both, since the newly arisen cause may disappear, in which case the original ruling would resume.

But if the change made by the governors to the dues is not sanctioned by the Sharīʿah and has no basis in independent legal reasoning, the dues remain subject to the original ruling, while the second is an invalid injustice to be rejected—whether they changed them by increasing or decreasing them. An increase is an injustice against the rights of the subjects, while a decrease is an injustice against the rights of the public treasury.

When the assessment in force is taken from the dīwān, the clerk who produces it from the dīwān records must produce both versions if the governor requesting it does not know its previous status. If he does know it, the clerk is not required to produce the first version for him, since he already knows it. It is sufficient to produce the second version while describing it as a newly instituted assessment.