Narrated Abu 'Is-haq: A man asked Al-Bara "O Abu '`Umara! Did you flee on the day (of the battle) of Hunain?" Al-Bara replied while I was listening, "As for Allah's Messenger (ﷺ) he did not flee on that day. Abu Sufyan bin Al- Harith was holding the reins of his mule and when the pagans attacked him, he dismounted and started saying, 'I am the Prophet, and there is no lie about it; I am the son of `Abdul Muttalib.' On that day nobody was seen braver than the Prophet.
Source: sunnah.com
Other translations
Arabic
حَدَّثَنَا عُبَيْدُ اللَّهِ، عَنْ إِسْرَائِيلَ، عَنْ أَبِي إِسْحَاقَ، قَالَ سَأَلَ رَجُلٌ الْبَرَاءَ ـ رضى الله عنه ـ فَقَالَ يَا أَبَا عُمَارَةَ، أَوَلَّيْتُمْ يَوْمَ حُنَيْنٍ قَالَ الْبَرَاءُ وَأَنَا أَسْمَعُ أَمَّا رَسُولُ اللَّهِ صلى الله عليه وسلم لَمْ يُوَلِّ يَوْمَئِذٍ، كَانَ أَبُو سُفْيَانَ بْنُ الْحَارِثِ آخِذًا بِعِنَانِ بَغْلَتِهِ، فَلَمَّا غَشِيَهُ الْمُشْرِكُونَ نَزَلَ، فَجَعَلَ يَقُولُ أَنَا النَّبِيُّ لاَ كَذِبْ، أَنَا ابْنُ عَبْدِ الْمُطَّلِبْ قَالَ فَمَا رُئِيَ مِنَ النَّاسِ يَوْمَئِذٍ أَشَدُّ مِنْهُ.
sunnah.com