Sahih Bukhari Volume 008, Book 075, Hadith Number 370.
Narated By Ibn Abi Aufa : Whenever somebody brought alms to the Prophet the used to say, "Allahumma Salli 'Alaihi (O Allah! Send Your Salat (Grace and Honor) on him)." Once when my father brought his alms to him, he said, "O Allah! Send Your Salat (Grace and Honor) on the family of Abi Aufa."