One-fifth of Booty to the Cause of Allah (Khumus)
Bukhari :: Book 4 :: Volume 53 :: Hadith 402
Narrated Abu Huraira:
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 Ka'ba undressed." And the day of Al-Hajj-ul-Akbar is the day of Nahr, and it called Al-Akbar because the people call the 'Umra 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-Wada' of the Prophets.
Source materials are from the University of Southern California MSA site|
Hadith eBooks converted from Imaan Star