Fatima is a specific case (19), and a report of a particular situation; it is possible that she informed him that she had no habit, or he knew that from someone else, or from the context of her condition. The hadith of ‘Adi ibn Thabit is general regarding every woman experiencing istihada, so it is more primary. Furthermore, the habit is stronger because its indication does not become void. As for color, when it exceeds the maximum of menstruation, its indication becomes void. Therefore, that whose indication does not become void is stronger and more worthy.

Section: If her menstruation was five days from the beginning of every month, then she experienced istihada and began to see three days of black blood at the beginning of every month: Whoever gives precedence to the habit says: She sits for five days every month, just as she used to sit before the istihada. Whoever gives precedence to the discrimination (tamyiz) makes (20) her menstruation the three days in which she sees the black blood, except that she does not abandon prayer in the first month for anything beyond the three; because we do not know that she is experiencing istihada except by the blood exceeding the maximum of menstruation, and we do not know that in the first month. Thus, when the blood exceeds the maximum of menstruation in the first month, we know it is istihada. Consequently, she does not sit in the second [month] for anything beyond the black blood. If she sees ten days of black blood every month, then it becomes red and is continuous: Whoever said that she pays no attention to what exceeds the habit until it repeats, did not assign her menstruation in the first two or three months except for five, the amount of her habit. Whoever said that when she exceeds the habit, she sits it from the first time, made her sit for fifteen days in the first month, then she performs ghusl and prays. In the second month, she sits for the days of the habit, which are the first five of the month according to those who give precedence to the habit over discrimination. And whoever gave precedence to discrimination and did not (21) consider repetition in it, made her sit for the entire ten days. If it repeats for three months in this description, the Qadi said: She sits for the ten in the fourth month, according to both narrations; because the increase over the habit is established by the repetition of the black [blood]. It is possible that she does not sit for an increase over her habit according to the view of one who gives precedence to the habit over discrimination; because if we made what is in excess of the habit from the discrimination a menstruation by its repetition, we would have made what is less than it an istihada by its repetition, and thus she would not sit.