What is the ruling if a pardon for *Qisas* (retaliation) in exchange for a slave is made, and the slave turns out to be rightfully owned by someone else (mustahiiq)?

Primary text

If a settlement for *Qisas* involves exchanging it for a slave, and it is later discovered that the slave rightfully belongs to another, the injured party receives the value (*qimah*) of the slave. This is the view held by all jurists considered herein. Similarly, if the slave turns out to be a free person, the injured party receives the value. Abu Yusuf and Muhammad support this ruling because the delivery of the substitute consideration became impossible, thus necessitating a return of the value, just as if the slave had been found to belong to another party.