وَعَنْ أَبِي هُرَيْرَةَ رضى الله عنه
قَالَ: قَالَ رَسُولُ اَللَّهِ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ -«إِنَّ تَحْتَ كُلِّ شَعْرَةٍ جَنَابَةً، فَاغْسِلُوا اَلشَّعْرَ، وَأَنْقُوا اَلْبَشَرَ»
The Messenger of Allah (sallallahu alayhi wa sallam) said: “There is Janabah (trace of sexual impurity) under every hair, so wash your hair and cleanse the skin.”
Bulugh al-Maram 151, Book 1, The Book of Purification, Hadith 151. 1 min read