آداب الجهاد
‘Abdullāh ibn ‘Umar (may Allah be pleased with him) reported that the Prophet (may Allah's peace and blessings be upon him) said: "When Allah, the Almighty, gathers together (on the Day of Judgment) all the earlier and later generations of mankind, a banner will be raised for every betrayer, and it will be said: 'This is the betrayal of so-and-so, the son of so-and-so.'"
عن عبد الله بن عمر -رضي الله عنهما- مرفوعاً: "إذا جمع الله -عز وجل- الأَوَّلِينَ والآخِرين: يرفع لكل غادر لِوَاءٌ، فيقال: هذه غَدْرَةُ فلان بن فلان".
شرح الحديث :
When Allah gathers together all the earlier and later generations on the Day of Resurrection, every betrayer will be brought up with a sign of his/her betrayal. This sign, which will take a form of a banner accompanying the betrayer, will disclose one's betrayal and brings him/her disgrace among people.