Ishaq said: "If it were permissible for anyone to set a time limit for them—that this time would be the maximum they menstruate, and to make all women uniform in that time by law—then the time the Prophet, may Allah bless him and grant him peace, set for Hamnah bint Jahsh, [which was] seven days of menstruation and twenty-three [days] of purity, would be the most likely of times; because the dominant state of women is such. The Prophet, may Allah bless him and grant him peace, said to her: 'As women menstruate and as they become pure.' There was an indication in this that this time should be [the standard] for all women. However, when the Prophet, may Allah bless him and grant him peace, established [a ruling] for the women who were experiencing irregular bleeding (istihada), and they asked him, he judged for them according to different rulings due to the differences in their natures that were built into them. We learned that the Prophet's instruction to Hamnah regarding the seven days was because of what she described and persisted in with the Prophet, may Allah bless him and grant him peace; for she said: 'I am experiencing a frequent and severe menstrual bleeding, which has prevented me from prayer and fasting.' He said: 'I prescribe for you the use of cotton (kursuf), for it removes the blood.' She was not satisfied with his words and said: 'It is more than that.' He said: 'Then use a pad (talajjami).' She said: 'It is more than that.' He said: 'Then wear a garment.' She said: 'I am gushing with it in a flood.' It was only then that he ordered her to rely on her discernment of her time, and that she should sit [refrain from prayer] for seven [days]. Therefore, when a woman is in the state of her irregular bleeding, the mixing of her menstruation, and her lack of knowledge of her times according to what we have described, we judge for her according to the ruling of Hamnah bint Jahsh, and we do not apply 279 the seven [days] to all women, because of these reasons we have described."