What is the required waiting period for a female slave who is not among those who experience menstrual periods (dhawat al-quru')?

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If a female slave is not among those who experience menstrual periods, her waiting period for purity (*istibra'*) is determined by the method established for a female slave whose mother was freed by her master (*umm walad*), as previously detailed. This ruling is based on the principle that if the master does not have sexual relations with the slave, the obligation of *istibra'* does not apply, similar to a woman who is married or observing the waiting period following divorce or widowhood. The rationale is that refraining from *istibra'* in such a case does not lead to the mixing of semen or confusion of lineage, unlike the situation where the slave is sexually possessed by her master.