Silsilat al-Ahadith al-Sahihah

Sayyiduna Anas bin Malik (may Allah be pleased with him) narrates that the Messenger of Allah (peace and blessings be upon him) asked for water for ablution, and washed his face, both hands, and both feet once each, and said: "This is the ablution without which Allah does not accept prayer." Then he (peace and blessings be upon him) asked for water and washed (the limbs) twice each and said: "This is the ablution; whoever performs ablution like this, Allah will grant him double the reward." Then he (peace and blessings be upon him) asked for water and washed (the limbs) three times each and said: "This is the ablution of your Prophet and the Prophets before him." Or he said: "This is my ablution and the ablution of the Prophets before me."