Sunan Ibn Majah Book 1, Hadith 193
"I heard Humran telling Abu Burdah in the mosque that he had heard 'Uthman bin 'Affan narrating that the Prophet had said" 'Whoever performs ablution perfectly as Allah has enjoined, then his prescribed prayer will serve as expiation for what is between them."
"Ibn 'Abbas came to me and asked me about this Hadith" meaning the Hadith, that she had narrated, saying that the Messenger of Allah performed ablution and washed his feet. "Ibn 'Abbas said: 'The people are insisting on washing their feet, but I do not find anything in the Qur'an except (the injunction to) wipe them.'"
He was sitting with the Prophet who said: 'No person's prayer is complete until he performs ablution properly as Allah has commanded him, washing his face, his arms up to the elbows, wiping his head and his feet up to the ankles.'"