The Messenger of Allah ﷺ said, "Among the natural acts," or "the natural acts are, rinsing the mouth, sniffing water into the nose, trimming the moustache, using the tooth-stick, clipping the nails, washing the finger joints, plucking the armpit hair, shaving the pubic hair, circumcision, and sprinkling water after urination."
حدثنا عفان حدثنا حماد حدثنا علي بن زيد عن سلمة بن محمد بن عمار بن ياسر
أن رسول الله ﷺ قال إن من الفطرة أو الفطرة المضمضة والاستنشاق وقص الشارب والسواك وتقليم الأظفار وغسل البراجم ونتف الإبط والاستحداد والاختتان والانتضاح
Its isnad is hasan, on account of Ali bin Zayd, and Muhammad bin Ammar bin Yasir is deemed "acceptable" (maqbul), his only narration being with Abu Dawud. The hadith is well known in the wording "five things are from the fitrah," and it has already appeared at 10287.See also Muslim 1/223, no. 261, Abu Dawud 1/14, no. 54, Tirmidhi 5/91, no. 2757, where he graded it hasan, Nasai 8/126, no. 5040, Ibn Majah 1/107, no. 294, and Tayalisi 1/360, no. 1853, Minhah.