It was written in her marriage contract that she had received her mahr but she has not received it and she has started to resent her husband

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Check below answers in case you are looking for other related questions:
Writing the dowry on a piece of silk
A Christian woman has the right to ask for a dowry from her Muslim husband

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Related Answers:
His father is unable to give his wife the dowry (mahr); can the son give it on behalf of his father?
Ruling on what comes before consummating the marriage with one’s wife; is it haraam to have intercourse after doing the marriage contract?
Is it permissible to give the mahr in a currency other than that mentioned in the marriage contract?
Writing the dowry on a piece of silk
A Christian woman has the right to ask for a dowry from her Muslim husband

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