It was narrated that Jabir said:
"The Messenger of Allah said: 'When the last people of this Ummah curse the first, (at that time) whoever conceals a Hadith will be concealing what Allah has revealed.'" (Maudu') (IT)
English reference (IT): Vol. 1, Book 1, Hadith 263 (IT)
Arabic reference (IT): Book 1, Hadith 275 (IT)