From Sahih Bukhari (Hadith 4657):
Narrated Humaid bin `Abdur-Rahman:Abu Huraira said that Abu Bakr sent him during the Hajj in which Abu Bakr was made the chief of the pilgrims by Allah's Messenger (ﷺ) before (the year of) Hajjat al-Wada` 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 Ka`ba 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
Reference: Bukhari 4657