Sahih Bukhari Volume 009, Book 092, Hadith Number 448.
Hadith Section/Book: Sahih Bukhari Sahih Bukhari Book 92. Holding Fast to the Qur'an and Sunnah
Narrated By Abu Said Al-Khudri : Allah's Apostle said, "Noah will be brought (before Allah) on the Day of Resurrection, and will be asked, 'Did you convey the message of Allah?" He will reply, 'Yes, O Lord.' And then Noah's nation will be asked, 'Did he (Noah) convey Allah's message to you?' They will reply, 'No warner came to us.' Then Noah will be asked, 'Who are your witnesses?' He will reply. '(My witnesses are) Muhammad and his followers.' Thereupon you (Muslims) will be brought and you will bear witness." Then the Prophet recited: 'And thus We have made of you (Muslims) a just and the best nation, that you might be witness over the nations, and the Apostle a witness over you.' (2.143)