صحیح مسلم · Hadith 7036

Qais b. 'Ubad reported: We said to 'Ammar: Was your fighting (on the side of 'Ali in the Battle of Siffin) a matter of your own choice or you got its hints from Allah's Messenger ( ‌صلی ‌اللہ ‌علیہ ‌وسلم ‌ ) for it, is likely for one to err in one's own discretion or was it because of any covenant that Allah's Messenger ( ‌صلی ‌اللہ ‌علیہ ‌وسلم ‌ ) got from you? He said: It was not because of any covenant that Allah's Messenger ( ‌صلی ‌اللہ ‌علیہ ‌وسلم ‌ ) got from us which he did get from other people, and he further said that Allah's Messenger ( ‌صلی ‌اللہ ‌علیہ ‌وسلم ‌ ) said: In my Ummah. And I think that Hudhaifa reported to me and according to Ghundar (the words are) that he said: In my Ummah, there would be twelve hypocrites and they would not be admitted to Paradise and they would not smell its odour, until the camel would pass through a needle's hole. Dubaila (ulcer) would be enough to (torment them) -a kind of flame of Fire which would appear in their shoulders and it would protrude from their chest.