Shaykh Muhammad Ibrahim bin Basheer
Benefit:
This hadith proves that prayer is not obligatory upon a woman during her menstrual period (hayd), but in the state of irregular bleeding (istihada), she will perform the prayer. Similarly, during menstruation, a woman does not fast, but she will make up (qada) those fasts later. It should be noted that a woman experiencing istihada has three conditions:
➊ If, before the onset of istihada, she used to have regular menstruation and its duration is known, then such a woman will not perform prayer or fasting during her known menstrual period, and the rulings of menstruation (hayd) will apply to her during those days. Outside of those days, the blood will be considered istihada, and the rulings of istihada will apply to her. This hadith refers to this situation.
➋ If, before the onset of istihada, she did not have menstruation, meaning that from the very beginning she has been experiencing the blood of istihada, and as soon as the bleeding started, istihada also began, then in such a case, she will differentiate between menstruation (hayd) and istihada based on the color, quality, and odor of the blood: if the blood is black, thick, or has a foul smell, then this is menstrual blood (hayd), and the rulings of menstruation will apply to her at that time. For blood with other characteristics, the rulings of istihada will apply.
➌ The third case is when neither her menstrual days are known nor is there any distinguishing sign in the blood by which istihada can be recognized. In this situation, if she began experiencing istihada from the onset of puberty, and the blood is of one type or of various characteristics, but it is not possible to determine menstruation, then this woman will act like the general women, i.e., she will consider as her menstruation the number of days that most women experience menstruation.
(al-Shaykh Muhammad Salih al-Munajjid)
Source: Musnad al-Humaydi: Commentary by Muhammad Ibrahim bin Bashir, Page: 304