Musnad Ahmad 1163:48

Waki’ narrated to us, he said: Al-A’mash narrated to us, from Salim, from Kurayb, who said: Ibn Abbas narrated to us, from his maternal aunt Maymunah, who said: "I placed water for the Prophet, peace and blessings of Allah be upon him, for a ritual bath (ghusl). He performed ghusl from janabah (major ritual impurity), and he tilted the vessel with his left hand onto his right, and washed his palms three times. Then he inserted his hand into the vessel and poured [water] over his private part. Then he rubbed his hand against the wall or the ground. Then he rinsed his mouth and sniffed water into his nose, and washed his face three times, and his forearms three times each. Then he poured water over his head three times. Then he poured water over the rest of his body. Then he moved aside and washed his feet."