Sunan Abi Dawud Book 2, Hadith 383
I offered prayer behind the Messenger of Allah (ﷺ). 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 Messenger of Allah (ﷺ) 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.
The Messenger of Allah (ﷺ) used to say in his tahajjud prayer(i.e. supererogatory prayer offered in or after the midnight) after he said the takbir; he then narrated the tradition to the same effect.
A young man from the Ansar sneezed behind the Messenger of Allah (ﷺ) while he was praying. He then said: Praise be to Allah, much, good, blessed, till our Lord is pleased (with us) in the affairs relating to this world and to the other world. When the Messenger of Allah (ﷺ) finished his prayer, he said: Who was the speaker of these words (in prayer)? The young man kept silence. He again asked: Who was the speaker of these words? He did not say wrong. He said: Messenger of Allah, I said these (words). I did not intend by them but good. He said: These words did not stay below the Throne of the Compassionate (Allah).