(1) باب الْفِطْرَةِ
It was narrated that Abu Hurairah said:
"The Messenger of Allah [SAW] said: 'Five things are of the Fitrah: Circumcision, shaving the pubes, plucking the armpit hair, clipping the nails and trimming the mustache.'" (IT)
Reference (IT): Sunan an-Nasa'i 5043 (IT)
In-book reference (IT): Book 48, Hadith 4 (IT)
English translation (IT): Vol. 6, Book 48, Hadith 5046 (IT)