Sahih al-Bukhari, Hadith 3339 ⓘ

Narrated Abu Sa`id: Allah's Messenger said, "Noah and his nation will come (on the Day of Resurrection and Allah will ask (Noah), "Did you convey (the Message)?' He will reply, 'Yes, O my Lord!' Then Allah will ask Noah's nation, 'Did Noah convey My Message to you?' They will reply, 'No, no prophet came to us.' Then Allah will ask Noah, 'Who will stand a witness for you?' He will reply, 'Muhammad and his followers (will stand witness for me).' So, I and my followers will stand as witnesses for him (that he conveyed Allah's Message)." That is, (the interpretation) of the Statement of Allah: "Thus we have made you a just and the best nation that you might be witnesses Over mankind.." (2.143)

حَدَّثَنَا مُوسَى بْنُ إِسْمَاعِيلَ، حَدَّثَنَا عَبْدُ الْوَاحِدِ بْنُ زِيَادٍ، حَدَّثَنَا الأَعْمَشُ، عَنْ أَبِي صَالِحٍ، عَنْ أَبِي سَعِيدٍ، قَالَ قَالَ رَسُولُ اللَّهِ صلى الله عليه وسلم ‏"‏ يَجِيءُ نُوحٌ وَأُمَّتُهُ فَيَقُولُ اللَّهُ تَعَالَى هَلْ بَلَّغْتَ فَيَقُولُ نَعَمْ، أَىْ رَبِّ‏.‏ فَيَقُولُ لأُمَّتِهِ هَلْ بَلَّغَكُمْ فَيَقُولُونَ لاَ، مَا جَاءَنَا مِنْ نَبِيٍّ‏.‏ فَيَقُولُ لِنُوحٍ مَنْ يَشْهَدُ لَكَ فَيَقُولُ مُحَمَّدٌ صلى الله عليه وسلم وَأُمَّتُهُ، فَنَشْهَدُ أَنَّهُ قَدْ بَلَّغَ، وَهْوَ قَوْلُهُ جَلَّ ذِكْرُهُ ‏{‏وَكَذَلِكَ جَعَلْنَاكُمْ أُمَّةً وَسَطًا لِتَكُونُوا شُهَدَاءَ عَلَى النَّاسِ‏}‏ وَالْوَسَطُ الْعَدْلُ ‏"‏‏.‏