Sayyidah Aishah (may Allah be pleased with her) says: The Messenger of Allah (peace and blessings be upon him) would first wash his hands, then perform ablution as for prayer, then put his palms into the water and run them through the roots of his hair, until, when he (peace and blessings be upon him) knew that the water had reached the skin, he would scoop three handfuls with his hand and pour them over his head, then wash (the rest of his body).
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الطهارة / 819
Sayyidah Aishah (may Allah be pleased with her) says: When the Messenger of Allah (peace and blessings be upon him) took the ritual bath for janabah (major impurity), he would first wash his hands, then pour (water) with his right hand over his left hand and wash his private part, then perform ablution as for prayer, then take water and put his fingers into the roots of his hair; then, when he (peace and blessings be upon him) saw that the water had reached the roots, he would pour three handfuls of water over his head, then pour water over his whole body, then wash his feet.
(b) In Sahih Muslim, at the end of the narration of Yahya bin Yahya, are these words: then he would wash his feet.
These words are gharib (unusual) but sahih (authentic); only Abu Mu'awiyah preserved them, among the trustworthy students of Hisham.
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الطهارة / 820