Musannaf Ibn Abi Shayba 1:793

Ibn ‘Ulayyah narrated to us, from Ayyub, from Abu al-Zubayr, from ‘Ubayd ibn ‘Umayr, who said: It reached ‘Aishah that ‘Abdullah ibn ‘Amr commands women, when they perform ghusl (ritual bath), to undo their hair. She said: "How strange of Ibn ‘Amr! Why does he not command them to shave their heads? I and the Messenger of Allah, may Allah bless him and grant him peace, used to perform ghusl from a single vessel, and I would do no more than pour three handfuls of water over my head."