Is it permissible for a son to seek retribution (qisas) from his father who intentionally killed his mother, and what is the ruling on that in the different schools of thought (madhahib)?

If a man intentionally kills his wife and has a child with her, then the retribution (qisas) is waived from him because his child inherits the right to retribution. This is a well-established ruling in the four schools of thought, for a father is not killed for his child whom he directly killed. Therefore, it is even more appropriate that he should not be killed for his crime against another person.