The Messenger of Allah ﷺ would put his head out to me from the mosque while he was in spiritual retreat, and I would wash it while I was menstruating.
أخبرنا محمد بن سلمة قال حدثنا ابن وهب عن عمرو بن الحارث وذكر آخر عن أبي الأسود عن عروة
كان رسول الله ﷺ يخرج إلي رأسه من المسجد وهو مجاور فأغسله وأنا حائض
Bukhari collected it, Book of Menstruation, chapter on the menstruating woman washing her husband's head and combing his hair, hadith no. 296, and Muslim, Book of Menstruation, chapter on the permissibility of the menstruating woman washing her husband's head... etc., hadith no. 297/8, from the hadith of Urwa, with this chain.