عَنْ ابْنِ عُمَرَؓ أَنّ رَسُولَ اللَّهِ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ قَالَ: إِنَّ الْغَادِرَ يُنْصَبُ لَهُ لِوَاءٌ يَوْمَ الْقِيَامَةِ، فَيُقَالُ هَذِهِ غَدْرَةُ فُلَانِ بْنِ فُلَانٍ(ابو داؤد شریف/باب فی الوفاء بالعھد)
Translation
It is narrated from Hazrat Ibn Umar (R.A) that the Holy Prophet (ﷺ) said that for a person who breaks a covenant, a flag will be planted on the Day of Resurrection, and it will be said to him that this is the betrayal of so-and-so, son of so-and-so (so that all the people may see his disgrace). (Sunan Abu Dawud Translated/Vol: 2)