The Duty of Nāsīyah
Issue No.477- “Nāsīyah” is a woman who has forgotten the duration of her menstrual period, its time, or both of them. In the case of forgetting the duration, if she sees blood for ten days or less, all of it is ḥayḍ, and if she sees blood for more than ten days, those days in which the blood bears the signs of ḥayḍ should be considered as ḥayḍ, provided that it is no less than three, and no more than ten days. However, if it is more than ten days, or the blood bears similar signs on all of the days, the obligatory precaution is to treat the first seven days as ḥayḍ and the rest as istiḥāḍah.
