Sahih al-Bukhari 3552
Sahih al-Bukhari · Book 61: Virtues and Merits of the Prophet (pbuh) and his Companions · The description of the Prophet (saws)
Narrated Abu 'Is-haq:
حَدَّثَنَا أَبُو نُعَيْمٍ ، حَدَّثَنَا زُهَيْرٌ ، عَنْ أَبِي إِسْحَاقَ ، قَالَ سُئِلَ الْبَرَاءُ أَكَانَ وَجْهُ النَّبِيِّ صلى الله عليه وسلم مِثْلَ السَّيْفِ قَالَ لاَ بَلْ مِثْلَ الْقَمَرِ.
Al-Bara' was asked, "Was the face of the Prophet (as bright) as a sword?" He said, "No, but (as bright) as a moon."