The father’s (ex-)wife is a mahram to his sons even if she did not bear him any children

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She married the one who committed zina with her after she gave birth and the nifaas bleeding stopped
Is the husband’s mother a mahram to the sons of his wife?

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Related Answers:
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She married the one who committed zina with her after she gave birth and the nifaas bleeding stopped
Is the husband’s mother a mahram to the sons of his wife?

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