Sunan Abi Dawud, Hadith 2463

'Aishah said: The Messenger of Allah used to observe I'tikaf in the mosque and put his head near me through the opening of the apartment, and I would wash his head. Musaddad said: "And I would comb it while I was menstruating."

حَدَّثَنَا سُلَيْمَانُ بْنُ حَرْبٍ، وَمُسَدَّدٌ، قَالاَ حَدَّثَنَا حَمَّادُ بْنُ زَيْدٍ، عَنْ هِشَامِ بْنِ عُرْوَةَ، عَنْ أَبِيهِ، عَنْ عَائِشَةَ، قَالَتْ كَانَ رَسُولُ اللَّهِ صلى الله عليه وسلم يَكُونُ مُعْتَكِفًا فِي الْمَسْجِدِ فَيُنَاوِلُنِي رَأْسَهُ مِنْ خَلَلِ الْحُجْرَةِ فَأَغْسِلُ رَأْسَهُ ‏.‏ وَقَالَ مُسَدَّدٌ فَأُرَجِّلُهُ وَأَنَا حَائِضٌ ‏.‏

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also referenced under: Hadith 2469 (DarusSalam)