Musannaf Ibn Abi Shayba 1:755

Abu Bakr narrated to us, he said: Waki’ narrated to us, from al-A’mash, from Salim, from Kurayb, from Ibn Abbas, from Maymunah, that the Prophet (peace and blessings of Allah be upon him) performed ghusl (full ablution) due to janabah (major ritual impurity). He then exited his place of bathing and moved aside, and he washed his feet.