Musnad Ahmad 25:1261

Hajjaj narrated to us, Sharik informed us, from Simak, from Ikrimah, from Ibn Abbas, who said: The Prophet, peace and blessings of Allah be upon him, and Maymunah became in a state of major ritual impurity (janabah). Maymunah performed ghusl (ritual bath) in a large basin, and some water remained. The Prophet, peace and blessings of Allah be upon him, intended to perform ghusl from it. She said: "O Messenger of Allah, I have already performed ghusl from it." He—meaning the Prophet, peace and blessings of Allah be upon him—said: "Indeed, water does not bear janabah," or he said: "Indeed, water does not become impure."