How is the Iddah calculated when based on months for a woman who has not menstruated or whose cycle has been lifted?
General Chapter
Al-Mughni
Book of Waiting Periods ('Iddah)
Primary text
If the Iddah is completed based on months, and subsequently she menstruates even for a moment, she must restart the Iddah. This is the view of the general consensus of the scholars of the major cities, including Sa'id ibn al-Musayyab, al-Hasan, Mujahid, Qatadah, al-Sha'bi, al-Nakha'i, al-Zuhri, al-Thawri, Malik, al-Shafi'i, Ishaq, Abu 'Ubayd, the proponents of *Ahl al-Ra'y*, the people of Medina, the people of Basra, and others. This is because the months serve as a substitute for menstruation; thus, when the actual item (menstruation) appears, the ruling of the substitute (months) is nullified, similar to how Tayammum becomes void upon finding water.
Supporting text
If the ruling is that *quru'* refers to the pure periods, there are two opinions regarding whether the preceding period of purity before the first menstruation counts as one *quru'*. One view is that it does count because it is a period of purity transitioned into menstruation, resembling the purity period between two menstrual flows. The second view, which aligns with the apparent statement of Imam al-Shafi'i, is that it does not count because *quru'* is defined as the purity between two established menstrual flows, and this preceding period had no preceding menstruation.