We have already discussed this. Some held that it is not permissible to allocate fayʾ to those entitled to zakat, just as those entitled to fayʾ are not entitled to zakat.
The second category is those serving public interests who do not have a fixed stipend. It is not valid to assign fayʾ to them without restriction, although it is permissible to assign them a portion of the kharaj funds, because what they receive constitutes grants made for public interests. If a portion of the kharaj funds is designated for them, it is governed by the rules of debt assignment and entitlement arising from a valid cause, not by the rules of assignment as an iqtāʿ. Its permissibility therefore depends on two conditions. First, the amount must be specified, and the cause establishing entitlement to it must already exist. Second, the kharaj funds must have fallen due and become payable, so that entitlement to them and their assignment may validly be established. With these two conditions, it falls outside the ruling of an iqtāʿ.
The third category is those entitled to the fixed stipends recorded in the dīwān, namely, the army. They are the people most entitled to receive such assignments, because they have fixed stipends paid to them as a matter of entitlement. These stipends are compensation for devoting themselves to protecting the Muslim polity and defending its sanctities.
Once it is established that they may receive such assignments, the nature of the kharaj funds must then be considered. Kharaj takes one of two forms: it may be jizya or rent. As for the kharaj that is jizya, it is not permanently established, because it is taken so long as disbelief remains and ceases when Islam occurs. It is therefore not permissible to assign it for more than one year, since entitlement to it thereafter is not assured. If he assigns it for one year after it has fallen due and become payable, the assignment is valid. But if he assigns it during the year before it becomes payable, it is not valid, because it has merely been assessed as becoming due.
As for kharaj that is rent, its obligation is permanently established, so it is valid to assign it for several years. It is not necessary to limit the assignment to a single year, unlike jizya, which is not permanently established.
In that case, assigning it falls into three categories. The first is that it be specified for a known number of years, such as assigning it for ten years. This is valid provided that two conditions are observed. First, the amount of the recipient’s stipend must be known to the person making the assignment; if it is unknown to him, the assignment is invalid. Second, the amount of the kharaj must be known both to the recipient and to the person making the assignment. If it is unknown to both of them, or to either one of them, the assignment is invalid. When this is the case, the kharaj must fall into one of two categories: