Musnad Ahmad 1153:5

Hushaym narrated to us, from ‘Umar ibn Abi Salamah, from Abu Salamah, from his father, from ‘Aishah, who said: "I used to perform ghusl (ritual bath) with the Messenger of Allah, may Allah bless him and grant him peace, from a single vessel, due to janabah (major ritual impurity)."