The Book of Virtue, Good Manners and Joining of the Ties of Relationship (Kitab Al-Birr was-Salat-I-wa'l-Adab)
Muslim :: Book 32 : Hadith 6241
'A'isha reported: I heard Allah's Messenger (may peace be upon him) as saying: There is nothing (in the form of trouble) that comes to a believer even if it is the pricking of a thorn that there is decreed for him by Allah good or his sins are obliterated.