Sahih al-Bukhari, Book 65, Hadith 4487 (In-Book) ⓘ

Narrated Abu Sa`id Al-Khudri: Allah's Messenger said, "Noah will be called on the Day of Resurrection and he will say, 'Labbaik and Sa`daik, O my Lord!' Allah will say, 'Did you convey the Message?' Noah will say, 'Yes.' His nation will then be asked, 'Did he convey the Message to you?' They will say, 'No Warner came to us.' Then Allah will say (to Noah), 'Who will bear witness in your favor?' He will say, 'Muhammad and his followers. So they (i.e. Muslims) will testify that he conveyed the Message. And the Apostle (Muhammad) will be a witness over yourselves, and that is what is meant by the Statement of Allah "Thus We have made of you a just and the best nation that you may be witnesses over mankind and the Apostle (Muhammad) will be a witness over yourselves." (2.143)

حَدَّثَنَا يُوسُفُ بْنُ رَاشِدٍ، حَدَّثَنَا جَرِيرٌ، وَأَبُو أُسَامَةَ ـ وَاللَّفْظُ لِجَرِيرٍ ـ عَنِ الأَعْمَشِ، عَنْ أَبِي صَالِحٍ، وَقَالَ أَبُو أُسَامَةَ، حَدَّثَنَا أَبُو صَالِحٍ، عَنْ أَبِي سَعِيدٍ الْخُدْرِيِّ، قَالَ قَالَ رَسُولُ اللَّهِ صلى الله عليه وسلم ‏"‏ يُدْعَى نُوحٌ يَوْمَ الْقِيَامَةِ فَيَقُولُ لَبَّيْكَ وَسَعْدَيْكَ يَا رَبِّ‏.‏ فَيَقُولُ هَلْ بَلَّغْتَ فَيَقُولُ نَعَمْ‏.‏ فَيُقَالُ لأُمَّتِهِ هَلْ بَلَّغَكُمْ فَيَقُولُونَ مَا أَتَانَا مِنْ نَذِيرٍ‏.‏ فَيَقُولُ مَنْ يَشْهَدُ لَكَ فَيَقُولُ مُحَمَّدٌ وَأُمَّتُهُ‏.‏ فَتَشْهَدُونَ أَنَّهُ قَدْ بَلَّغَ ‏"‏‏.‏ ‏{‏وَيَكُونَ الرَّسُولُ عَلَيْكُمْ شَهِيدًا‏}‏ فَذَلِكَ قَوْلُهُ جَلَّ ذِكْرُهُ ‏{‏وَكَذَلِكَ جَعَلْنَاكُمْ أُمَّةً وَسَطًا لِتَكُونُوا شُهَدَاءَ عَلَى النَّاسِ وَيَكُونَ الرَّسُولُ عَلَيْكُمْ شَهِيدًا‏}‏ وَالْوَسَطُ الْعَدْلُ‏.‏