Abu Bakr, on the day of Nahr (i.e. slaughtering of animals for sacrifice), sent me in the company of others to make this announcement: "After this year, no pagan will be allowed to perform the Hajj, and none will be allowed to perform the Tawaf of the Kaʿba undressed." And the day of Al-Hajj-ul-Akbar is the day of Nahr, and it called Al-Akbar because the people call the ʿUmra Al-Hajj-ul-Asghar (i.e. the minor Hajj). Abu Bakr threw back the pagans' covenant that year, and therefore, no pagan performed the Hajj in the year of Hajj-ul-Wadaʿ of the Prophets.  

بَعَثَنِي أَبُو بَكْرٍ ؓ فِيمَنْ يُؤَذِّنُ يَوْمَ النَّحْرِ بِمِنًى لاَ يَحُجُّ بَعْدَ الْعَامِ مُشْرِكٌ وَلاَ يَطُوفُ بِالْبَيْتِ عُرْيَانٌ وَيَوْمُ الْحَجِّ الأَكْبَرِ يَوْمُ النَّحْرِ وَإِنَّمَا قِيلَ الأَكْبَرُ مِنْ أَجْلِ قَوْلِ النَّاسِ الْحَجُّ الأَصْغَرُ فَنَبَذَ أَبُو بَكْرٍ إِلَى النَّاسِ فِي ذَلِكَ الْعَامِ فَلَمْ يَحُجَّ عَامَ حَجَّةِ الْوَدَاعِ الَّذِي حَجَّ فِيهِ النَّبِيُّ ﷺ مُشْرِكٌ  

Abu Huraira said that Abu Bakr sent him during the Hajj in which Abu Bakr was made the chief of the pilgrims by Messenger of Allah ﷺ before (the year of) Hajjat al-Wadaʿ in a group (of announcers) to announce before the people; 'No pagan shall perform the Hajj after this year, and none shall perform the Tawaf around the Kaʿba in a naked state. Humaid used to say The Day of Nahr is the day of Al- Hajj Al-Akbar (the Greatest Day) because of the narration of Abu Huraira.  

أَخْبَرَهُ أَنَّ أَبَا بَكْرٍ ؓ بَعَثَهُ فِي الْحَجَّةِ الَّتِي أَمَّرَهُ رَسُولُ اللَّهِ ﷺ عَلَيْهَا قَبْلَ حَجَّةِ الْوَدَاعِ فِي رَهْطٍ يُؤَذِّنُ فِي النَّاسِ أَنْ لاَ يَحُجَّنَّ بَعْدَ الْعَامِ مُشْرِكٌ وَلاَ يَطُوفَ بِالْبَيْتِ عُرْيَانٌ فَكَانَ حُمَيْدٌ يَقُولُ يَوْمُ النَّحْرِ يَوْمُ الْحَجِّ الأَكْبَرِ مِنْ أَجْلِ حَدِيثِ أَبِي هُرَيْرَةَ