Sahih al-Bukhari, Book 77, Hadith 120 (In-Book) ⓘ
Narrated Anas : The hair of the Prophet used to hang down up to his shoulders.
حَدَّثَنَا إِسْحَاقُ، أَخْبَرَنَا حَبَّانُ، حَدَّثَنَا هَمَّامٌ، حَدَّثَنَا قَتَادَةُ، حَدَّثَنَا أَنَسٌ، أَنَّ النَّبِيَّ صلى الله عليه وسلم كَانَ يَضْرِبُ شَعَرُهُ مَنْكِبَيْهِ.
also referenced under: Hadith 5903 (DarusSalam) & Volume 7, Book 72, Hadith 790 (USC-MSA)