Abu Dawud Book 7, Hadith Number 2409.
Chapter : Not known.
Narated By AbuBakrah : The Prophet (PBUH) said: One of you should not say: I fasted the whole of Ramadan, and I prayed during the night in the whole of Ramadan. I do not know whether he disliked the purification; or he (the narrator) said: He must have slept a little and taken rest.