Rejecting the sunnah and praying behind someone who does

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Justification for following the Sunnah
They start fasting one day after the people do so and break the fast one day after the people do so

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Should He Forsake His Family Who Reject the Sunnah?
His father asks him to buy cigarettes for him
It is not permissible for a man to obey his parents by making his wife not wear niqaab
Justification for following the Sunnah
They start fasting one day after the people do so and break the fast one day after the people do so

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