Musnad Ahmad 1153:1955

'Abd al-A'la narrated to us, from Ma'mar, from al-Zuhri, from 'Urwah, from 'Aishah, that she used to comb the hair of the Prophet, may God bless him and grant him peace, while she was menstruating and he was in retreat (i'tikaf) in the mosque. He would extend his head to her while she was in her chamber.