Musannaf Ibn Abi Shayba 3:3839

Waki’ narrated to us, he said: Sufyan narrated to us, from ‘Abd al-Karim, from ‘Amr ibn Sa’id, from ‘A’isha: That the Prophet, peace and blessings of Allah be upon him, entered upon her, and a freedwoman of theirs hid herself. The Prophet, peace and blessings of Allah be upon him, said: "Is she menstruating?" They said: "Yes." So he tore a piece from his turban and said: "Cover your head with this."