Sunan an-Nasa'i, Book 48, Hadith 1 (In-Book) ⓘ
It was narrated from 'Aishah that: The Messenger of Allah [SAW] said: "Ten things are part of the Fitrah: Trimming the mustache, trimming the nails, washing the joints, letting the beard grow, using the Siwak, rinsing the nose, plucking the armpit hairs, shaving the pubes, and washing with water (after relieving oneself)." Mus'ab bin Shaibah said: "I have forgotten the tenth, unless it was rinsing the mouth."
أَخْبَرَنَا إِسْحَاقُ بْنُ إِبْرَاهِيمَ، قَالَ أَنْبَأَنَا وَكِيعٌ، قَالَ حَدَّثَنَا زَكَرِيَّا بْنُ أَبِي زَائِدَةَ، عَنْ مُصْعَبِ بْنِ شَيْبَةَ، عَنْ طَلْقِ بْنِ حَبِيبٍ، عَنْ عَبْدِ اللَّهِ بْنِ الزُّبَيْرِ، عَنْ عَائِشَةَ، عَنْ رَسُولِ اللَّهِ صلى الله عليه وسلم " عَشَرَةٌ مِنَ الْفِطْرَةِ قَصُّ الشَّارِبِ وَقَصُّ الأَظْفَارِ وَغَسْلُ الْبَرَاجِمِ وَإِعْفَاءُ اللِّحْيَةِ وَالسِّوَاكُ وَالاِسْتِنْشَاقُ وَنَتْفُ الإِبْطِ وَحَلْقُ الْعَانَةِ وَانْتِقَاصُ الْمَاءِ " . قَالَ مُصْعَبٌ وَنَسِيتُ الْعَاشِرَةَ إِلاَّ أَنْ تَكُونَ الْمَضْمَضَةَ .
also referenced under: Hadith 5040 (Reference) & Volume 6, Book 48, Hadith 5043 (DarusSalam)