The Book of Adornment
48/59. Chapter:
Wearing One's Hair Long
Sunan an-Nasai
أَخْبَرَنَا عَلِيُّ بْنُ حُجْرٍ، قَالَ أَنْبَأَنَا إِسْمَاعِيلُ، عَنْ حُمَيْدٍ، عَنْ أَنَسٍ، قَالَ كَانَ شَعْرُ النَّبِيِّ صلى الله عليه وسلم إِلَى نِصْفِ أُذُنَيْهِ .
It was narrated from Anas that: The hair of the Prophet [SAW] came halfway down his ears.
Reference : Sunan an-Nasa'i 5234In-book reference : Book 48, Hadith 195English translation : Vol. 6, Book 48, Hadith 5236