What is the ruling on menstrual discharge when the black blood exhibits variations in duration across different months?
Chapter on Menstruation
Al-Mughni
Book of Purification
Primary text
When the menstrual flow is variable, such as seeing five days of black blood in the first month, four in the second, and three in the third, or other differences like five, six, and seven days respectively, there are differing scholarly opinions. According to one established opinion, the black blood is considered menses in all circumstances. However, according to the opinion of Al-Qadi (the Judge), the black blood is considered menses only for the duration that conforms to the established customary period (Ada).
Supporting text
Al-Qadi's view stipulates that only the duration corresponding to the custom (three days in the first instance, five in the second, and four in the third) is considered menses initially. Any excess that repeats subsequently becomes menses, but if it does not repeat, it is not considered menses. Following this view, a woman should abstain from prayer and fasting during the first and second months only for the minimum time observed by a woman who has not yet established a menstrual pattern (la tamyiz laha). If she is a beginner (mubtadi'ah), she abstains only for one day and one night. Whether she abstains for the duration that repeats in the third or fourth month depends on differing narrations regarding how the custom (Ada) is established. In this varied case, the ruling resembles that of a beginner whose perceived blood does not exceed the maximum duration of menses, where the red blood is treated as purity (Tuhur) and the black blood is treated as menstrual blood in the standard case.