Good Manners and Form (Al-Adab)
Ṣaḥīḥ al-Bukhārī 6177
الْغَادِرُ يُرْفَعُ لَهُ لِوَاءٌ يَوْمَ الْقِيَامَةِ، يُقَالُ هَذِهِ غَدْرَةُ فُلاَنِ بْنِ فُلاَنٍ
al-ghādiru yurfaʿu lah liwāʾun yawma al-qiyāmah, yuqālu hadhihi ghadrah fulāni bni fulānin
Transliteration generated from the Arabic vowel marks
The full narration
Narrated Ibn `Umar:The Prophet (ﷺ) 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
Source
Ṣaḥīḥ al-Bukhārī · 6177
Ṣaḥīḥ