If either spouse—or that spouse’s free child or mukātab (a slave bound by a manumission contract)—were to purchase the other spouse, even partially, their marriage is immediately annulled.

Any woman whose intercourse is forbidden to a man by virtue of a marriage contract is likewise forbidden to him through ownership, except a slave woman from among the People of the Book. Should he unite, in a single contract, a woman who is permissible with one who is impermissible, the contract is valid only for the woman who is permissible.

The marriage of a khunthā mushkil (a person of indeterminate intersex status) is not valid until the individual’s sex has been clarified.