558 - Sufyan ibn 'Abd al-Malik informed me of that, from Ibn al-Mubarak, from them both.
Ibn al-Mubarak said: "I am able to adjudicate the matter of a woman whose menstruation is more than ten days, whose known menstrual periods are likewise, and who does not experience deviation other than as one whose periods are less than ten days, by referring her matter to ten [days], and I consider what is beyond that to be irregular bleeding (istihada). And for a woman whose menstrual periods are known, I say: She has never menstruated (1) at all; so if a woman's periods are known, then her periods are whatever they were."
Ibn al-Mubarak said: "What is most reliable to me personally is that when a virgin first sees blood, she should refrain [from prayer/fasting] for three days." And Ibn al-Mubarak spoke the truth.
Abu Ya'qub said: "Whenever the blood is recognized as menstrual blood, and she experiences a period of purity as women experience it, then that is menstruation; she refrains from prayer. The same applies to two days. If someone from among them denies this, 278 and says: 'We do not say, if she refrains for two days with a moderate menstruation, that this is menstruation; we do not consider it a natural physical state, but rather we say: She is not menstruating,' it is said to him: You have agreed that menstruation can be three [days], even some of them said: two days and most of the third day. Thus, it would be incumbent upon you in your analogy not to consider two days and part of the third as menstruation, due to (2) the rarity of this occurring in women."
(1) Thus it is in the original, and perhaps the correct reading is "tahid" (she menstruates). (2) Thus it is in the original, and perhaps the correct reading is "li-qillati" (due to the rarity).