What is the minimum age for a female to begin menstruating?
Chapter on Menstruation
Al-Mughni
Book of Purification
Primary text
The minimum age for a female to menstruate is nine years old. This is established because a young child does not menstruate, supported by the statement in the Quran: {And those who have not menstruated} (Quran 3:4). Furthermore, reference is made to observed reality, where no women are accustomed to menstruation below this age. Since the wisdom behind menstrual blood is related to nurturing pregnancy, the absence of capability for pregnancy implies the absence of this wisdom, similar to semen. The appearance of this blood is a sign of puberty. Aisha reported that when a girl reaches nine years, she is considered a woman, meaning she is subject to the rulings of a woman. This is the position held by Al-Shafi'i.
Supporting text
Al-Shafi'i is reported to have observed a grandmother who was twenty-one years old, implying she conceived before the age of ten, and her daughter conceived similarly. If a girl aged nine sees blood, she must cease prayer because it occurs during a time where menstruation is possible. If the flow lasts a day and a night, it constitutes menstruation, establishing her puberty and all its associated rulings. If it stops sooner, it is considered corrupted blood (*dam fasaad*), establishing none of the major rulings.