Musnad Ahmad 1153:1217

Hashim narrated to us, Israel narrated to us, from Jabir, from Amir, from Masruq, from Aisha, 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 while we were both in a state of janabah (major ritual impurity). However, water does not become junub (ritually impure)."