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') (ES)
English reference (ES): Vol. 1, Book 1, Hadith 263 (ES)
Arabic reference (ES): Book 1, Hadith 275 (ES)