Musnad Ahmad 1153:1545

'Abd al-Rahman narrated to us, from Sufyan, from Mansur, from Ibrahim, from al-Aswad, from 'Aisha, who said: "When I would menstruate, the Messenger of Allah (peace and blessings of Allah be upon him) would command me to wrap an izar (waist-wrapper) around myself, then he would engage in physical intimacy with me." And the Messenger of Allah (peace and blessings of Allah be upon him) would bathe with me from a single vessel while we were both in a state of major ritual impurity (janabah). And the Messenger of Allah (peace and blessings of Allah be upon him) would extend his head toward me while he was in itikaf (seclusion in the mosque), and I would wash it while I was menstruating.