The Prophet ﷺ said, "Every traitor will have a banner on the Day of Resurrection by which he will be recognized, fixed at his backside."
حدثنا أبو الوليد حدثنا شعبة حدثنا خليد بن جعفر عن أبي نضرة
عن النبي ﷺ لكل غادر لواء يوم القيامة يعرف به عند استه
Its isnad is sahih. Abu Walid is Tayalisi, Hisham bin Abdul-Malik, the commander of the faithful in hadith, and the hadith has already appeared at 10979.