As for the condition that makes their registration in the dīwān permissible, five qualifications are taken into consideration. The first is maturity, for a child is counted among the dependents. The second is freedom. The basic principle is that slaves may not be assigned stipends individually in the dīwān of the combatants. This was ʿUmar’s view, and it is the apparent meaning of Ahmad’s statement in the report of al-Marwazī, in which he cited ʿUmar as saying: “Every Muslim has a share in it, except slaves; they have no share in it.” Al-Shāfiʿī held this view as well. Some Iraqi jurists, however, held that slaves could be assigned stipends individually in the dīwān of the combatants; this was Abū Bakr’s view.
The third is Islam, so that he may defend the faith through his belief and strengthen it through his sincere counsel and striving. If a dhimmī (non-Muslim under Muslim protection) were registered among them, that would not be permissible; and if one of the Muslims registered among them were to apostatize, his registration would be cancelled. This accords with Ahmad’s position, for he prohibited seeking the assistance of unbelievers in jihad.
The fourth is freedom from impairments that prevent combat. Thus, it is not permissible for one who is chronically disabled, blind, or an amputee to be registered. A mute or deaf person, however, may be registered. As for one who is lame, if he is a cavalryman, he is registered; but if he is an infantryman, he is excluded.
The fifth is that he possess the courage to advance into battle and knowledge of combat. If his strength is insufficient for advancing into battle, or his knowledge of combat is limited, it is not permissible to register him, since he would be assigned to something he is incapable of doing.
Once all these qualifications are fully present, his registration in the army dīwān depends on an application and approval: the application must come from him when he is free from all other work, while the ruler’s role is to accept it when the need arises. If he is well known by name and distinguished in standing, it is not appropriate, once he has been registered in the dīwān, to furnish his entry with additional identifying descriptions. If he is obscure among the people, however, his entry should be furnished and described: his age, stature, complexion, and facial features should be recorded, along with whatever distinguishes him from others, lest names coincide or someone falsely claim his stipend at the time of payment. He should also be attached to a naqīb (representative) over him or to an ʿarīf (overseer) assigned to him, who is held accountable for him.
As for their ordering in the dīwān once they have been registered, it is considered from two perspectives: one general and the other particular. The general perspective concerns the ordering of tribes and ethnic groups, so that each tribe is distinguished from the others and each ethnic group from those unlike it. Those who differ should not be combined, nor those who belong together separated, so that the summons of the dīwān follows a recognized order and rationale, thereby eliminating dispute and rivalry.
Accordingly, they must be either Arabs or non-Arabs. If they are Arabs, some genealogies unite them while others distinguish them. Their tribes are therefore ordered according to their closeness in kinship to the Messenger of Allah (peace and blessings be upon him), as ʿUmar did when he recorded them. The ordering begins with the foundational lineage, followed by what branches from it.