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

Another principle concerns menstruation and non-menstrual bleeding. Questions concerning non-menstrual bleeding are among the most difficult in the chapters on ritual purification. Three rulings have been transmitted from the Prophet, may Allah bless him and grant him peace, on this subject: a woman with an established menstrual pattern should follow that pattern; a woman able to distinguish between the types of bleeding should act on that distinction; and a woman who cannot determine her period, having neither an established pattern nor the ability to distinguish the bleeding, should regard herself as menstruating for the usual duration of women’s periods—six or seven days—and may combine two prayers if she wishes.

The first two rulings are recorded in the authentic hadith collections. The third is found in the hadith of Hamna bint Jahsh, transmitted by the compilers of the Sunan and graded authentic by al-Tirmidhī. Abū Dāwūd and others also transmitted a report concerning Sahla bint Suhayl conveying part of the same meaning. Ahmad applied these three Prophetic rulings respectively to the woman with an established menstrual pattern, the woman able to distinguish the bleeding, and the woman unable to determine her period. When both an established pattern and distinguishable bleeding are present, the established pattern takes precedence according to the sounder of the two reports of his position, as indicated in most of the hadiths.