Musnad Ahmad 1034:79

Aswad ibn Amir narrated to us, Shu'bah narrated to us, from Qatadah, from Abu Nadrah, from Qays, who said: I said to Ammar, "Do you see this action of yours that you have done regarding the affair of Ali as an opinion you reached, or is it something the Messenger of Allah (peace and blessings of Allah be upon him) entrusted to you?" He said: "The Messenger of Allah (peace and blessings of Allah be upon him) did not entrust anything to us that he did not entrust to all the people. However, Hudhayfah informed me from the Prophet (peace and blessings of Allah be upon him) that he said: 'Among my companions are twelve hypocrites; eight of them will not enter Paradise until the camel enters through the eye of a needle.'"