Musnad Ahmad 1153:629

'Affan narrated to us, Hammad bin Zayd narrated to us, he said: Ayyub narrated to us, from Muhammad, that 'Aishah stayed with Safiyyah, the mother of Talhah al-Talhat, and she saw daughters of hers praying without head coverings (khumur), and they had reached puberty (menstruated). He said: 'Aishah said: "None of them shall pray unless she is wearing a head covering (khimar). For the Messenger of Allah (peace and blessings of Allah be upon him) entered upon me, and there was a young girl in my lap, so he threw his lower garment (hizār) over me and said: 'Divide it between this one and the young girl who is in the lap of Umm Salamah, for I do not see her but that she has reached puberty,' or 'I do not see them both but that they have reached puberty.'"