Sayyiduna Jubayr bin Mut'im (may Allah be pleased with him) says: The people disputed about the ritual bath in the presence of the Messenger of Allah (peace and blessings be upon him). Some of them said: I wash my head in such and such a way. The Messenger of Allah (peace and blessings be upon him) said: "As for me, I pour three handfuls of water over my head."
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الطهارة / 834