divorce, and the maximum durations of menstrual and postnatal bleeding, so that these may be distinguished from irregular bleeding. As for the maximum interval of purity, it has no limit, because as long as a woman remains pure, she prays, fasts, and may have intercourse with her husband, however long or short that interval may be. Regarding the minimum interval of purity, there are four views:
The first is Ibn al-Mājishūn’s view, which he also narrated from Mālik: its minimum is five days. Thus, the shorter the interval of purity, the longer the menstruation, and the shorter the menstruation, the longer the interval of purity. This is a weak view, because it implies that a woman may menstruate for more than half her life, which is contradicted by transmitted evidence.
The second is Sahnūn’s view, also implied by al-Mudawwanah according to Ibn Abī Zayd’s interpretation: its minimum is eight days.
The third is the narration of al-Tūnisī from Mālik and that of Asbagh from Ibn al-Qāsim: its minimum is ten days.
The fourth is Muhammad ibn Maslamah’s view: its minimum is fifteen days. This fourth view has some basis in analogical reasoning. Allah, Blessed and Exalted, prescribed a waiting period of three periods for divorced free women who menstruate, saying:
“Divorced women shall wait for three periods.” [al-Baqarah: 228]
He prescribed a waiting period of three months for women who have ceased menstruating, saying:
“As for those of your women who no longer menstruate, if you are in doubt, their waiting period is three months, and likewise for those who have not menstruated.” [al-Talāq: 4]
Thus, He made each month correspond to an interval of purity and a menstrual period. There are only four possible combinations: first, the maximum interval of purity and the maximum duration of menstruation; second, the minimum interval of purity and the minimum duration of menstruation; third, the maximum interval of purity and the minimum duration of menstruation; and fourth, the minimum interval of purity and the maximum duration of menstruation.
The maximum interval of purity combined with the maximum duration of menstruation, or the minimum interval of purity combined with the minimum duration of menstruation, cannot be correct, because there is no upper limit to the interval of purity. Nor can the minimum interval of purity combined with the minimum duration of menstruation be correct, because the longest proposed minimum interval of purity is fifteen days, and the longest proposed minimum duration of menstruation is five days, leaving ten days of the month unaccounted for. Once these three combinations have been ruled out, only the fourth remains: that the month corresponds to the minimum interval of purity and the maximum duration of