[2] (V.12:52).
a) Narrated Ibn ‘Umarرضي الله عنهما : The Prophet صلى الله عليه وسلم 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, Vol.8, Hadith No.196)
b) See the footnote of (V.4:145).