Volume 1 · Book 4 · Hadith 145
Once the Prophet entered a lavatory and I placed water for his ablution. He asked, "Who placed it?" He was informed accordingly and so he said, "O Allah! Make him (Ibn 'Abbas) a learned scholar in religion (Islam)."
— Sahih Bukhari, Volume 1, Book 4: Ablutions (Wudu'), Hadith #145