Musnad Ahmad 31:625

'Affan narrated to us, Shu'bah narrated to us, from Khulayd ibn Ja'far, from Abu Nadrah, from Abu Sa'id al-Khudri, from the Prophet, peace and blessings of Allah be upon him, who said: "For every treacherous person there shall be a banner on the Day of Resurrection at his posterior."