Musnad Abi Ya'la 4625 — she heard a woman asking Sayyidah Aishah

It is narrated from Buhayyah (may Allah have mercy on her) that she heard a woman asking Sayyidah Aishah (may Allah be pleased with her) about a woman whose menstruation had become irregular and who did not know how to pray. Sayyidah Aishah (may Allah be pleased with her) said to her: "I asked the Messenger of Allah (peace and blessings be upon him) about a woman whose menstruation had become irregular and who was bleeding profusely, so that she could not understand how to pray. The Messenger of Allah (peace and blessings be upon him) commanded me to tell her: 'Let her look at the length of time her menstruation used to last each month when it was regular, and let her refrain (from prayer) for that many days and nights and estimate them; then (when that period has passed) let her take a bath for purification, then bind a cloth (as a loincloth) and pray, for I hope that this is an effect from Satan and that Allah Almighty will remove it from her, if Allah wills.'" Sayyidah Aishah (may Allah be pleased with her) said: "So I instructed that woman to do so, and Allah removed that illness from her. So you too instruct your companion to do the same."