A woman who used to menstruate but whose menses cease before she reaches the age of menopause, without knowing the cause, must wait nine months and then observe the post-menopausal ʿidda.
If she knows the cause of the cessation—such as illness1, breastfeeding, or the like—she remains in waiting until the menses return and then bases her ʿidda on them, or until she becomes post-menopausal, in which case she observes the ʿidda of a post-menopausal woman.2
Section
If an unrelated man has intercourse with her during her ʿidda—whether under shubha (a mistaken assumption of permissibility), through a void marriage contract, or through outright fornication3—she must first complete the ʿidda for the original marriage and then observe a separate ʿidda for the second act.
If the husband who irrevocably divorced her has intercourse with her intentionally, he is treated like any outsider; if it occurs under shubha, she must recommence the ʿidda from the beginning.
The ʿidda is multiplied by the number of men who had intercourse with her under shubha, but not by the number involved in fornication.4 While she remains in her ʿidda, it is forbidden for her husband to have vaginal intercourse with her if she has been penetrated under shubha or through fornication.