What is the ruling if a man marries a woman believing her to be free but she turns out to be a slave?

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If a man marries a woman believing her to be free, but she is discovered to be a slave, he has the option (khiyar) to proceed or annul the marriage, similar to a stipulated condition. This view is affirmed by Ahmad for this specific case, and it is also applied when a man marries a woman believing her to be Muslim, but she turns out to be a disbeliever, or when a woman marries a man believing him to be free, but he turns out to be a slave. The basis for granting this option is that the servitude (riq) involves greater harm, as it affects the status of the offspring and impedes the full enjoyment of marital rights, thereby equating the situation to marrying a disbeliever.