in regard to what had been reported from the Companions, such as women’s head coverings and low-fitting caps.

It is well known that this area contains a measure of leniency consonant with the foundational principles of the Sharia and with the sound reports established from the Prophet (peace and blessings be upon him).

Know that anyone who has placed an interpretation upon these reports—for example, that wiping over a turban suffices only when accompanied by wiping part of the head, or the like—has not considered all the reports together. Anyone who does consider them in their entirety will attain certain knowledge to the contrary.

[Dry Ablution]

Another foundational principle concerns dry ablution. The soundest hadith on this subject is the hadith of ʿAmmār ibn Yāsir (may Allah be pleased with him), which explicitly states that a single strike suffices for the face and hands. No comparable hadith on this subject contradicts it. The hadith jurists, including Ahmad and others, adopted it. This is sounder than the view that two strikes are obligatory, with the hands wiped up to the elbows—as held by Abū Hanīfa and by al-Shāfiʿī in his later position—or that two strikes are required, with the hands wiped up to the wrists.

[Menstruation and Non-Menstrual Bleeding]

Another foundational principle concerns menstruation and non-menstrual bleeding. Questions relating to non-menstrual bleeding are among the most difficult areas of purification. Three Sunnah rulings have been reported from the Prophet (peace and blessings be upon him): one concerning a woman with an established menstrual pattern, who must refer back to her usual pattern; one concerning a woman able to distinguish between the types of blood, who must act upon that distinction; and one concerning a woman left uncertain, who has no established pattern and cannot distinguish between the types of blood—