From Sahih Bukhari (Hadith 6177):
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
Reference: Bukhari 6177