The Book of Adornment
48/7. Chapter:
Combing the Hair Every Other Day
Sunan an-Nasai
أَخْبَرَنَا عَلِيُّ بْنُ حُجْرٍ، قَالَ حَدَّثَنَا عِيسَى بْنُ يُونُسَ، عَنْ هِشَامِ بْنِ حَسَّانَ، عَنِ الْحَسَنِ، عَنْ عَبْدِ اللَّهِ بْنِ مُغَفَّلٍ، قَالَ نَهَى رَسُولُ اللَّهِ صلى الله عليه وسلم عَنِ التَّرَجُّلِ إِلاَّ غِبًّا .
It was narrated that 'Abdullah bin Mughaffal said: "The Messenger of Allah [SAW] forbade combing one's hair, except every other day."
Reference : Sunan an-Nasa'i 5055In-book reference : Book 48, Hadith 16English translation : Vol. 6, Book 48, Hadith 5058