Musnad Abu Ya'la al-Mawsili 150:368

Muhammad ibn al-Minhal narrated to us, Yazid ibn Zuray' narrated to us, Aban ibn Sam'ah narrated to us, from Ikrimah, from Aisha, who said: I used to perform ghusl, I and the Prophet, peace and blessings of Allah be upon him, from one vessel. He would begin before me.