Nevertheless, it is considered a revocable contract, for the work involved is undefined—unlike a binding lease. Hence it is permissible to promise a physician a reward for achieving a cure, just as the people (1) of that village offered the Companions of the Prophet ﷺ a reward for curing their chieftain by means of ruqyah when they had hosted them but then refused (2). By contrast, it is not permissible to hire a physician on the basis of a guaranteed cure, because such an outcome is beyond his power and the work itself cannot be precisely fixed (3).

Section: Clarifying the schools of law concerning who may stake the prize in a race, what is lawful therein, and what is forbidden

This issue has three scenarios:

1. The stake is provided by someone other than the two contestants—either the ruler or a member of the public.
2. The stake is provided by only one of the two contestants.
3. The stake is provided jointly by both contestants.

• A group forbade either contestant, or one of them alone, from putting up the prize, holding that it may only be offered by the ruler or by some other person. This is the view of al-Qāsim ibn Muḥammad (4).