What is the ruling on qisas for castration, meaning the deliberate crushing of the testicles until sterility?

Retribution (Qisas) is prescribed for the soul and the limbs, whenever it is possible to exact it without injustice, for Allah Almighty says: (And there is for you in [the law of] Qisas [retribution] life, O you [people] of understanding, that you may become righteous) [Al-Baqarah: 179]. And because of what Al-Bukhari and Muslim narrated from Anas (may Allah be pleased with him): "A Jew crushed the head of a slave girl between two stones. So the Prophet (peace and blessings of Allah be upon him) ordered that his head be crushed between two stones."

Similarly, in the story of the 'Urayniyyin, whose eyes the Prophet (peace and blessings of Allah be upon him) gouged out, as a retribution for their gouging out the eyes of the shepherds. Thus, equivalence in Qisas is not among the forbidden mutilation (Muthlah).

The correct view is that retribution is exacted for every wound, whenever it is possible to exact Qisas for it. So, whoever severs another's testicle, Qisas is exacted from him, if the safety of the other testicle is ensured. And whoever removes the function of the testicle without severing it, then Qisas from him is by removing the function, by a means that does not lead to injustice.

It is not permissible to exact Qisas except in the presence of the ruler or his deputy, for fear of aggression and mutilation of the offender.