´Narrated Anas:` from the Prophet (ﷺ), that he (ﷺ) fixed the time as every forty nights for them to trimming the fingernails, taking from the mustache, and shaving the pubic hairs.
Hadith Referenceسنن ترمذي / كتاب الأدب عن رسول الله صلى الله عليه وسلم / 2758
Hadith Gradingالألبانی:صحيح، ابن ماجة (295) | زبیر علی زئی:(2758) إسناده ضعيف / د 4200
´Narrated Anas bin Malik:` "[The Messenger of Allah (ﷺ)] fixed the time for us paring the mustache, trimming the fingernails, shaving the pubic hairs and plucking the underarm hairs - that we not leave it for more than forty days."
Hadith Referenceسنن ترمذي / كتاب الأدب عن رسول الله صلى الله عليه وسلم / 2759