خصال الفطرة
Five grooming and hygiene practices described as part of natural human disposition: trimming the mustache, letting the beard grow, using the tooth-stick, cutting the nails, and washing the finger joints.
خَمْسٌ مِنَ الْفِطْرَةِ: الْخِتَانُ، وَالِاسْتِحْدَادُ، وَقَصُّ الشَّارِبِ، وَتَقْلِيمُ الْأَظْفَارِ، وَنَتْفُ الْإِبِطِ
“Five things are part of natural disposition: circumcision, shaving pubic hair, trimming the mustache, clipping the nails, and plucking the underarm hair.” (meaning, not a literal translation)
A related narration adds using the tooth-stick and rinsing the nose to a longer list of ten fitra practices (Sahih Muslim 261), which is why this entry's title references five while some classical discussions group a broader set together — different hadith enumerate somewhat different, overlapping lists.
Classical physicians grouped these under general bodily hygiene — reducing sites where bacteria and odor accumulate, well before germ theory offered a mechanism. Ibn al-Qayyim discusses these alongside miswak and nose-rinsing (covered in their own entries) as part of a coherent, repeated body-hygiene routine rather than isolated, unrelated instructions.
Regular trimming of body hair in these areas and nail care are recognized in modern hygiene guidance as reducing bacterial accumulation and infection risk — a straightforward alignment between the classical instruction and contemporary hygiene practice.