Sahih al-Bukhari, Book 78, Hadith 201 (In-Book) ⓘ
Narrated Ibn `Umar: The Prophet said, "For every betrayer (perfidious person), a flag will be raised on the Day of Resurrection, and it will be announced (publicly) 'This is the betrayal (perfidy) of so-and-so, the son of so-and-so.' "
حَدَّثَنَا مُسَدَّدٌ، حَدَّثَنَا يَحْيَى، عَنْ عُبَيْدِ اللَّهِ، عَنْ نَافِعٍ، عَنِ ابْنِ عُمَرَ ـ رضى الله عنهما ـ عَنِ النَّبِيِّ صلى الله عليه وسلم قَالَ " الْغَادِرُ يُرْفَعُ لَهُ لِوَاءٌ يَوْمَ الْقِيَامَةِ، يُقَالُ هَذِهِ غَدْرَةُ فُلاَنِ بْنِ فُلاَنٍ " .
also referenced under: Hadith 6177 (DarusSalam) & Volume 8, Book 73, Hadith 196 (USC-MSA)