Hadith 6:1042
Waki’ narrated to us, from Sufyan, from Abu Ishaq, from Najiya, from Ali, from the Prophet (may Allah bless him and grant him peace), with the like of it. And he said: "So he commanded me to perform ghusl (full ritual washing)."
حدثنا وكيع عن سفيان عن أبي إسحاق عن ناجية عن علي عن النبي صلى الله عليه وسلم بنحوه وقال فأمرني بالغسل