Prayer (Kitab Al-Salat): Details of Commencing Prayer
Dawud :: Book 3 : Hadith 772
Narrated Rifa'ah ibn Rafi':
I offered prayer behind the Apostle of Allah (peace_be_upon_him). Rifa'ah sneezed. The narrator Qutaybah did not mention the name Rifa'ah (but he said: I sneezed). So I said: Praise be to Allah, praise much, good and blessed therein, blessed thereupon, as our Lord likes and is pleased. When the Apostle of Allah (peace_be_upon_him) finished his prayer, he turned and said: Who was the speaker in prayer? He then narrated the rest of the tradition like that of Malik and completed it.