Mishkat al-Masabih 562, 563

Asmāʾ daughter of ʿUmays said: ‘I told the Messenger of Allah, “Fāṭima daughter of Abū Ḥubaysh has had irregular bleeding for some time and has not been praying.” The Messenger of Allah said, “Glory be to Allah! This is from Satan. Let her sit in a tub. When she sees yellow discoloration on the water’s surface, let her perform one ritual bath for the noon and afternoon prayers, one for the sunset and night prayers, and one for the dawn prayer. She should perform ablution between those times.”’ Abū Dāwūd transmitted it and said: ‘Mujāhid reported from Ibn ʿAbbās that when performing ritual baths became difficult for her, he instructed her to combine the two prayers.’ (Graded ṣaḥīḥ, as a Companion report.)