Is sexual intercourse between a father and his son's female slave permissible?

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Sexual intercourse between a father and his son's female slave is not permissible. The evidence for this ruling rests on the prohibition of intercourse outside of marriage or legal ownership as mentioned in Quran {23:5-6}, and the fact that the slave is neither the father's wife nor his property. Furthermore, it is permissible for the son to have intercourse with her, and a woman cannot be lawful for two men simultaneously. If the father engages in intercourse with her, no Hadd punishment is incumbent upon him. Ahmad explicitly stated this ruling. This is supported by the principle that doubts repel prescribed punishments (Hadd). The father has a semblance of right over her due to the Prophet's statement, "You and your wealth belong to your father." The father is not liable to capital punishment (Qisas) for killing his son; thus, if a right belonging to an individual (like Qisas) is waived due to doubt, the right belonging to God (like Hadd) is waived a fortiori. Likewise, the father is not subject to amputation for stealing his own property or lashing for slandering his own slave.