I say: This is the sound conclusion, so hold fast to it. Further evidence that anything other than water does not suffice for menstrual blood is the Prophet’s statement in the second hadith: “Water is sufficient for you.” Its implication is that anything other than water is not sufficient. Reflect on this.
Second: Menstrual blood must be washed away, even if it is only a small amount, because of the general nature of the command. But must some cleansing substance be used to remove the remaining trace of impurity, such as lote-tree leaves, soap, and the like? The Hanafis and others held that this is not obligatory, citing the absence of any mention of such a cleansing agent in the first two hadiths. Al-Shafi‘i and the Prophet’s Household, as stated in Nayl al-Awtar (1/35–36), held that it is obligatory, citing the command to use lote-tree leaves in the third hadith, since they are a cleansing substance. Al-San‘ani inclined to this view, saying in Subul al-Salam (1/55), in response to the Moroccan commentator’s statement, “The first view is more apparent”:
“It may be said that the command has been reported to wash menstrual blood with water and lote-tree leaves, and lote-tree leaves are a cleansing substance. The hadith which mentions this is of the highest authenticity, as you have learned. It therefore qualifies what is stated without restriction in other reports, such as the two preceding hadiths. Such cleansing treatment is confined to menstrual blood, and other impurities are not analogized to it, since the conditions for analogy are not fulfilled. The hadith, ‘Its trace will not harm you,’ and Aisha’s statement, ‘It did not go away,’ are understood to refer to what remains after using a cleansing agent.”
I say: This is closer to the apparent meaning of the hadith. It is strange that Ibn Hazm did not address it at all in al-Muhalla (1/102), as though it had not reached him.
Third: Menstrual blood is impure, because of the command to wash it, and there is consensus on this, as al-Shawkani (1/35) related from al-Nawawi. As for other kinds of blood, I know of no proof that they are impure, apart from what al-Qurtubi mentioned in his exegesis (2/221): “The scholars agree that blood is impure.” He stated it thus—“blood”—without qualification, but this is open to criticism on two grounds:
First: Ibn Rushd mentioned this with a qualification, saying in Bidayat al-Mujtahid (1/62):