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.' "
Sahih al-Bukhari Book 78, Hadith 201
← Previous Hadith When the delegation of `Abdul Qais came to the Prophet, he said, "Welcome, O the delegation who have come! Neither you will have disgrace, nor you will regret." They said, "O Allah's Messenger (ﷺ)! We are a group from the tribe of Ar-Rabi`a, and between you and us there is the tribe of Mudar and we cannot come to you except in the sacred months. So please order us to do something good (religious deeds) so that we may enter Paradise by doing that, and also that we may order our people who are behind us (whom we have left behind at home) to follow it." He said, "Four and four:" offer prayers perfectly , pay the Zakat, (obligatory charity), fast the month of Ramadan, and give one-fifth of the war booty (in Allah's cause), and do not drink in (containers called) Ad-Duba,' Al-Hantam, An-Naqir and Al-Muzaffat."

Sahih al-Bukhari Book 78, Hadith 200 Next Hadith → Allah's Messenger (ﷺ) said, "A flag will be fixed on the Day of Resurrection for every betrayer, and it will be announced (publicly in front of everybody), 'This is the betrayal (perfidy) so-and-so, the son of soand- so."

Sahih al-Bukhari Book 78, Hadith 202