Musnad Ahmad 1007:94

Hassan ibn Yahya, from the people of Merv, narrated to us, An-Nadr ibn Shumayl informed us, Shu'bah narrated to us, from Abu Maslamah, from Abu Nadrah, from Abu Sa'id al-Khudri, who said: One who is better than me, Abu Qatadah, informed me that the Messenger of Allah (peace and blessings of Allah be upon him) said to Ammar ibn Yasir: "The rebellious faction will kill you."