Urwa reported,

Urwa was asked, "May a menstruating woman serve me, or may a woman in a state of major ritual impurity come close to me?"Urwa replied, "All of that is a simple matter to me. Any of them may serve me, and there is no harm upon anyone in that. Ayesha informed me that she used to comb the hair of the Messenger of Allah ﷺ while she was menstruating. At that time the Messenger of Allah ﷺ was in seclusion in the mosque, and he would lean his head toward her while she was in her chamber, and she would comb it while menstruating."

Bukhari 296

Sahih

حدثنا إبراهيم بن موسى قال أخبرنا هشام بن يوسف أن ابن جريج أخبرهم قال أخبرني هشام بن عروة

عن عروة

أنه سئل أتخدمني الحائض أو تدنو مني المرأة وهي جنب فقال عروة كل ذلك علي هين وكل ذلك تخدمني وليس على أحد في ذلك بأس أخبرتني عائشة أنها كانت ترجل تعني رأس رسول الله ﷺ وهي حائض ورسول الله ﷺ حينئذ مجاور في المسجد يدني لها رأسه وهي في حجرتها فترجله وهي حائض

البخاري 296صحيح
Contents
Reference
Commentary
Ayat
Collection
Sahih Bukhari
Book
Menstruation
Chapter
Washing and combing of the husband's hair by a menstruating woman
Numbering
Darussalam 296
Bukhari 296