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].

وعن ابن مسعود، وابن عمر، وأنس رضي الله عنهم قالوا: قال النبي ﷺ : " لكل غادر لواء يوم القيامة، يقال: هذه غدرة فلان" ((متفق عليه)).