Musnad Ahmad 25:264

Ali ibn Ishaq narrated to us, Abdullah narrated to us, Sufyan informed us, from Simak, from Ikrimah, from Ibn Abbas: That one of the wives of the Prophet, peace and blessings of Allah be upon him, performed ghusl (ritual bath) from janabah (major ritual impurity), and the Prophet, peace and blessings of Allah be upon him, performed wudu (ablution) with the remaining water. She mentioned that to him, and he said: "Indeed, nothing makes water impure."