Is it permissible for a Mukatab (a slave contracted for manumission) to take a female slave as a concubine without his master's permission?

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It is not permissible for a Mukatab to take a female slave as a concubine (*tasarri*) without the permission of his master. This prohibition exists because the Mukatab's ownership is incomplete, and taking a concubine causes harm (*taghrir*) to the female slave. If the master grants permission, the action becomes permissible because the restriction pertains to the slave's limited rights, which the master can waive, similar to permission granted to a fully enslaved male.