Musannaf Ibn Abi Shayba 1:58

Abu Usama narrated to us, from Sufyan, from Musa ibn Abi Aisha, from Amr ibn Shu’ayb, from his father, from his grandfather, that a man asked the Prophet, may Allah bless him and grant him peace, about ablution (wudu). He called for water and performed ablution three times [for each part]. Then he said, "This is the purification. Whoever increases or decreases [this] has transgressed and done wrong."