Sayyiduna Ibn Abbas (may Allah be pleased with them both) says: Shall I not tell you about the ablution of the Messenger of Allah (peace and blessings be upon him)? Then he called for a vessel of water and began taking a single scoop from it for each limb. In another narration it is that he said: the Prophet (peace and blessings be upon him) performed ablution washing each part once.
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الطهارة / 377