Musnad Ahmad 1163:7

Hashim ibn al-Qasim narrated to us, he said: Sharik narrated to us, from Simak, from Ikrimah, from Ibn Abbas, from Maymunah, the wife of the Prophet, may Allah bless him and grant him peace, she said: I and the Messenger of Allah, may Allah bless him and grant him peace, became in a state of major ritual impurity (janabah). I performed ghusl from a large bowl, and some water remained. The Messenger of Allah, may Allah bless him and grant him peace, came to perform ghusl from it. I said: "I have already performed ghusl from it." He said: "Indeed, water does not have janabah upon it," or: "Nothing makes it impure," and he performed ghusl from it.