“I once asked al-Rida’ (a.s.), saying, ‘I pray to Allah to keep my soul in service for your cause, my brother died and I married his widow and my paternal uncle came saying that he had married her secretly. I asked her about it but she denied it vehemently saying, ‘There has never been such a thing between us.’ He (the Imam) said, ‘Her confirming makes it obligatory on you to accept her words and her denial makes it obligatory on him to accept her denial.’”