رِيَاضُ الصَّالِحِينَ
Riyad as-Salihin 1585
The Book of the Prohibited actions
Prohibition of the Treachery and Breaking one's Covenant
وَعَنْ ابْنِ مَسْعُودٍ، وَابْنِ عُمَرَ، وَأَنَسٍ رَضِيَ اللَّه عَنْهُمْ قَالُوا: قَالَ النَّبِيُّ صَلَّى اللَّه عَلَيْهِ وَسَلَّمَ : لِكُلِّ غَادِرٍ لِوَاءٌ يَوْمَ الْقِيَامَةِ، يُقَالُ: هَذِهِ غَدْرَةُ فُلاَنٍ ((مُتَّفَقٌ عَلَيْهِ)).
Ibn Mas'ud, Ibn 'Umar and Anas (May Allah be pleased with them) said: The Prophet (ﷺ) said, "For every one who breaks his covenant, there will be a (huge) flag on the Day of Resurrection and it will be said: 'This flag proclaims a breach of covenant by so-and-so."' [Al-Bukhari and Muslim].
Riyad as-Salihin, 1585