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.
Sahih al-Bukhari Book 58, Hadith 19
← Previous Hadith I went to the Prophet (ﷺ) during the Ghazwa of Tabuk while he was sitting in a leather tent. He said, "Count six signs that indicate the approach of the Hour: my death, the conquest of Jerusalem, a plague that will afflict you (and kill you in great numbers) as the plague that afflicts sheep, the increase of wealth to such an extent that even if one is given one hundred Dinars, he will not be satisfied; then an affliction which no Arab house will escape, and then a truce between you and Bani Al-Asfar (i.e. the Byzantines) who will betray you and attack you under eighty flags. Under each flag will be twelve thousand soldiers.

Sahih al-Bukhari Book 58, Hadith 18 Next Hadith → Allah's Messenger (ﷺ) said, "Whoever has (the following) four characteristics will be a pure hypocrite: "If he speaks, he tells a lie; if he gives a promise, he breaks it, if he makes a covenant he proves treacherous; and if he quarrels, he behaves in a very imprudent evil insulting manner (unjust). And whoever has one of these characteristics, has one characteristic of a hypocrite, unless he gives it us."

Sahih al-Bukhari Book 58, Hadith 20