Silsilat al-Ahadith al-Sahihah

Amr bin Shu'aib narrates from his father, and he from his grandfather Abdullah bin Amr (may Allah be pleased with them), who says: A Bedouin came to the Prophet Muhammad (peace and blessings be upon him) and asked about ablution. The Prophet (peace and blessings be upon him) demonstrated ablution to him, in which he washed each limb three times. Then he said: "Ablution is done in this way. Whoever washes (the limbs) more than this (amount), he does wrong, exceeds the limit, and acts unjustly."