(51) باب الْخِتَانِ بَعْدَ الْكِبَرِ وَنَتْفِ الإِبْطِ
Narrated Abu Huraira:
The Prophet (ﷺ) said "Five things are in accordance with Al Fitra (i.e. the tradition of prophets): to be circumcised, to shave the pelvic region, to pull out the hair of the armpits, to cut short the moustaches, and to clip the nails.'
Reference: Sahih al-Bukhari 6297
In-book reference: Book 79, Hadith 69
USC-MSA web (English) reference(deprecated numbering scheme): Vol. 8, Book 74, Hadith 312