Is it permissible to set a specific time frame for completing the work in a Ja'alah contract?
General Chapter
Al-Mughni
Book of Lost-and-Found Property
Primary text
If the work is specified, such as returning a slave from Basra, building a specific wall, or sewing a specific shirt for a set reward, the contract is valid; it is more valid than when the work is unspecified. If a specific duration is stipulated, such as 'Whoever returns my slave from Iraq within a month, shall have one Dinar,' or 'Whoever sews this shirt for me in a day, shall have one Dirham,' this is valid because if the duration is valid when unspecified, it is more valid when specified.
Supporting text
The difference between this and Ijarah is manifold. First, Ja'alah tolerates uncertainty (gharar), being valid with unknown work and duration, unlike Ijarah. Second, Ja'alah is a permissible contract, so entering it with gharar does not impose undue harm, whereas Ijarah is binding, thus imposing the gharar once entered. Third, if Ijarah is time-bound, the work is obligatory for the entire duration; combining a time limit with work might lead to obligation beyond the agreed scope or voids in the time frame, which is not the case in Ja'alah where the reward is contingent only upon completing the specific work within that stipulated time.