The Book on Government
33/10. Chapter:
The obligation of fulfilling oaths of allegiance is owed to the first of two Caliphs
Sahih Muslim
حَدَّثَنَا أَبُو بَكْرِ بْنُ أَبِي شَيْبَةَ، وَعَبْدُ اللَّهِ بْنُ بَرَّادٍ الأَشْعَرِيُّ، قَالاَ حَدَّثَنَا عَبْدُ اللَّهِ، بْنُ إِدْرِيسَ عَنِ الْحَسَنِ بْنِ فُرَاتٍ، عَنْ أَبِيهِ، بِهَذَا الإِسْنَادِ مِثْلَهُ .
The same tradition has been transmitted by a different chain of narrators.
Reference : Sahih Muslim 1842bIn-book reference : Book 33, Hadith 72USC-MSA web (English) reference : Book 20, Hadith 4544