Sahih al-Bukhari 5904
Book 77: Dress · Narrated by Anas
Arabic
حَدَّثَنَا مُوسَى بْنُ إِسْمَاعِيلَ، حَدَّثَنَا هَمَّامٌ، عَنْ قَتَادَةَ، عَنْ أَنَسٍ، كَانَ يَضْرِبُ شَعَرُ النَّبِيِّ صلى الله عليه وسلم مَنْكِبَيْهِ.
English translation
Narrated Anas: The head-hair of the Prophet (ﷺ) used to hang down to his shoulders
Reference: Sahih al-Bukhari 5904, Book of Dress. English translation by Dr. Muhammad Muhsin Khan.