What is required for the legal retribution (Qisas) in wounds to be obligatory?

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Three conditions must be met for Qisas regarding wounds to be obligatory. First, the act must be purely intentional (Amd Mahd). Accidental harm (Khata) does not incur Qisas by scholarly consensus, as Qisas is not applied in homicide, which is the original basis. Second, there must be parity (Takafu) between the injurer and the injured, meaning the injurer would face capital punishment if they had killed the victim. Examples include a free Muslim against a free Muslim. Those whose lives are not forfeit if they kill, such as a Muslim against a non-Muslim resident or a free person against a slave, are not subject to Qisas for injuries less than death. Third, the retribution must be executable without injustice or excess, based on Quran 16:126 and Quran 2:194, which mandate retaliation in kind. The injurer's blood remains protected except for the extent of the injury committed.