(7) باب التَّرَجُّلِ غِبًّا
It was narrated that Al-Hasan and Muhammad said:
"Combing one's hair (should be done) every other day."
Reference: Sunan an-Nasa'i 5057
In-book reference: Book 48, Hadith 18
English translation: Vol. 6, Book 48, Hadith 5060