Some of the people of Medina disagreed with Malik on this matter and said: 'Once the number of nights and days she used to menstruate in the month have passed, she is a mustahadah at that point, and she does not have the right to observe an additional period (istizhar) after her menstrual cycles.'

This position is more correct and more similar to the established Sunnah known from the Prophet (peace and blessings of Allah be upon him), as he said to the mustahadah: 'Sit for the number of nights and days' she used to menstruate. There is no istizhar in the hadith of the Prophet (peace and blessings of Allah be upon him), and a known Sunnah is not nullified by such a thing. The practice of istizhar for a day or two after her menstrual cycles was only validated by Ibn Abbas, al-Hasan, Ata, and their peers, so whoever says that is not to be censured. The well-known position is what we have described regarding the statement of the Prophet (peace and blessings of Allah be upon him) on refraining from istizhar.

Malik and the people of Medina unanimously agreed that the maximum for menstruation is fifteen days, and the minimum is [one day], so that is considered menstruation according to them, whether she had known menstrual cycles or not. They said: 'This is a woman whose menstruation exceeded her time until it reached the maximum period that women menstruate, then it ceased.' They said: 'We do not consider the maximum for menstruation to be anything other than fifteen days.' Malik said: 'If a woman saw blood for a period of menstruation, or a day, then saw purity for a day, and she continued in that manner for months, that would be menstruation and purity.' He argued using the statement of the Prophet (peace and blessings of Allah be upon him) to Fatima: 'If the menstruation arrives, then leave the prayer, and if it departs, then pray.' In his view, the arrival of blood is the visual observation, and its departure is the purity.

So, if the woman's time is known, she should not exceed it in the month as a regular period. If she sees an increase once beyond the maximum days of her known cycles, and the blood she sees is fresh, or yellow or turbid, or continuous flowing blood, then she is a mustahadah. This is based on what the Prophet (peace and blessings of Allah be upon him) established as the time for menstrual cycles for those who know their cycles. The woman asked him: 'I have become a mustahadah, so clarify the cycles for me.' Her asking the Prophet (peace and blessings of Allah be upon him) is evidence that her menstrual days had increased beyond her previous cycles, yet he did not assign her a time, nor did he command her to sit for more than the days of her cycles.