Musnad Ahmad 1153:1391

Muhammad ibn Ja'far narrated to us, he said: Shu'bah narrated to us, from 'Ata' ibn al-Sa'ib, he said: I heard Abu Salamah, he said: I entered upon 'Aishah and asked her about the ghusl (ritual bath) of the Messenger of Allah, may Allah bless him and grant him peace, from janabah (major ritual impurity). She said: "His vessel would be brought, and he would wash his hands three times. Then he would pour from the vessel onto his private part and wash it. Then he would pour with his right hand onto his left and wash it. Then he would rinse his mouth and sniff water into his nose. Then he would pour over his head three times, then he would wash the rest of his body."