He said: "This is her timing. She should repeat the fasting if she had fasted during those days, because it is menses." I said: "What if she sat for one day, but the blood continued for ten, then it ceased for her, and in the second month it ceased for her after seven, and it varied for her, and so on?" He said: "She should look to the least of that and make it her timing and her days of menses."
"The first is: She who has known days; she acts according to the days she used to have.
The second is: She who had days, but they became confused for her." Ahmad said: "Fatima - may Allah be pleased with her - came and said: 'I suffer from isti'hada (prolonged non-menstrual bleeding) and do not become pure; should I abandon prayer?'" Ahmad said: "She had forgotten the days she used to sit; so this one acts based on the onset and the cessation of the blood." Abu 'Abd Allah said: "The onset of the blood is black and recognizable."
"The third is: The hadith of Hamnah: 'I flow with a heavy gush, it is more than that,' so he said to her: 'Observe menstruation according to the knowledge of Allah for six or seven days.'"
