He said to Hamna: "Menstruate for six days or seven days in the knowledge of Allah, then perform ghusl (full ablution) and pray for twenty-four nights or twenty-three nights, and their days." Thus, he prioritized her menstruation over the period of purity, then commanded her to pray and fast during the remainder of it. Because (18) the beginner (mustabda'ah) observes her days from the beginning of the month, even though she has no habit, the same applies to the woman who has forgotten. Furthermore, menstrual blood is blood of innate nature (jibillah), whereas istihadah (irregular bleeding) is incidental; therefore, when she sees blood, it is necessary to prioritize the menstrual blood. The second view is that she observes her days of the month through inquiry (taharri) and ijtihad. This is the opinion of Abu Bakr and Ibn Abi Musa, because the Prophet (may Allah bless him and grant him peace) referred her back to her ijtihad regarding the quantity with his statement: "six or seven." Thus, it applies equally to the time. Also, inquiry (19) has a place in menstruation, evidenced by the fact that the woman who can distinguish (mumayyizah) returns to the quality of the blood; the same applies to its time. If the entire time appears equal to her, and nothing strongly prevails in her opinion, then it is determined that she observes it from the beginning of the month, due to the lack of evidence for anything else.

The second category: The woman who has forgotten her number but not her time, such as the one who knows her menstruation is in the first ten days of the month but does not know the number. Regarding the quantity she should observe, she is like the confused woman (mutahayyirah): she observes six or seven days in the more correct of the two narrations. However, she observes them within the ten days and not otherwise. As to whether she observes them from the beginning of the ten days or by inquiry, there are two views. If she says: "I know that I was menstruating at the beginning of the month, but I do not know the end of it," or "I was menstruating at the end of the month, but I do not know the beginning of it," or "I do not know whether that was the beginning of my menstruation or the end of it," we designate for her the day she knew and she completes the remainder of her menstruation from what follows it in the first scenario, from what precedes it in the second, and by inquiry in the third, or from what follows the beginning of the month, based on the two different views.

The third category: The woman who has forgotten her time but not her number. This type is divided into two kinds: The first is that she does not know any time for herself at all, such as if she knows that her menstruation is five days. In this case, she observes five days (20) of every month, either from the beginning of it or by inquiry, based on the two differing views. The second is: