Musnad Ahmad 1153:1090

Yazid narrated to us, he said: Shu'bah informed us, from 'Ata' ibn al-Sa'ib, from Abu Salamah, he said: I asked 'Aishah 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: "He used to wash his hands three times, then he would wash his private part, then he would wash his hands, then he would rinse his mouth and sniff water into his nose, then he would pour [water] over his head, then he would pour [water] over the rest of his body."