The menstruating woman must make up the fasts but not the prayers. Neither worship is valid from her while the bleeding continues; rather, both are forbidden. Vaginal intercourse with her is likewise unlawful; if the husband nonetheless does so, he must pay an expiation of one dinar or half a dinar, while he may enjoy anything short of intercourse. When the bleeding stops but she has not yet performed the ritual bath, only fasting and the issuance of divorce become lawful for her.

The novice—one who has no previous menstrual habit—abstains for the minimum period, then performs the ritual bath and prays. If the bleeding returns and lasts up to the maximum duration or anything less, she bathes as soon as it ceases⦗1⦘. Should that pattern repeat three times, it is deemed menstruation, and she must make up whatever acts of worship became obligatory during those days⦗2⦘. If the bleeding exceeds the maximum, she is treated as a woman with non-menstrual bleeding. When part of her blood is black and part red, and the black portion neither exceeds the maximum nor falls short of the minimum, the black blood is counted as her menstruation⦗3⦘, which she observes again in the second month, while the red discharge is classified as non-menstrual. If her blood shows no such distinction, she refrains for the usual duration of menses each month.

A woman with non-menstrual bleeding who has an established habit—even if she can differentiate between types of blood—adheres to her habit. If she has forgotten it, she relies on reliable distinguishing signs; when none exist, she follows the common length of menstruation, just like one who knows the timing of her period but has forgotten its length. If she knows the number of days but has forgotten when they occur in the month—even if she thinks it is mid-month—she counts those days from the beginning of the month, as does a woman with neither habit nor distinguishing signs. Should her habit lengthen, or shift earlier or later, whatever new pattern recurs three times is her menstruation; anything shorter than the former habit is purity, and whenever the bleeding returns within her habitual period she refrains for it.

Yellowish or brownish discharge that appears during the habitual time is considered menstruation, and any woman who sees blood for a single day