Musnad Abu Ya'la al-Mawsili 209:138

Abu Khaythama narrated to us, Mu'awiyah ibn 'Amr narrated to us, he said: Za'idah narrated to us, 'Ammar ibn Abi Mu'awiyah al-Bajali narrated to us, from Abu Salamah, he said: Umm Salamah narrated to me that she used to perform ghusl (ritual bath) with the Messenger of Allah, may Allah bless him and grant him peace, from janabah (major ritual impurity) from a single vessel.