Musnad Ahmad 33:76

Muhammad ibn Ja'far narrated to us, Shu'bah narrated to us, from Makhul, from Muhammad ibn Ali, from Jabir ibn Abdullah: "The Messenger of Allah (peace and blessings of Allah be upon him) used to pour three [handfuls of water] over his head." Shu'bah said: "I think he meant in the ritual bath (ghusl) from major ritual impurity (janabah)." A man from Banu Hashim said: "My hair is thick." Jabir said: "The Messenger of Allah (peace and blessings of Allah be upon him) had more hair than you, and it was better."