The Messenger of Allah ﷺ said: Ten are the acts according to fitrah (nature): clipping the moustache, letting the beard grow, using the tooth-stick, cleansing the nose (Al-Istinshaq) with water, cutting the nails, washing the finger joints, plucking the hair under the arm-pits, shaving the pubes, and cleansing one's private parts (after easing or urinating) with water. The narrator said: I have forgotten the tenth, but it may have been rinsing the mouth.  

قَالَ رَسُولُ اللَّهِ ﷺ عَشْرٌ مِنَ الْفِطْرَةِ قَصُّ الشَّارِبِ وَإِعْفَاءُ اللِّحْيَةِ وَالسِّوَاكُ وَالاِسْتِنْشَاقُ بِالْمَاءِ وَقَصُّ الأَظْفَارِ وَغَسْلُ الْبَرَاجِمِ وَنَتْفُ الإِبِطِ وَحَلْقُ الْعَانَةِ وَانْتِقَاصُ الْمَاءِ يَعْنِي الاِسْتِنْجَاءَ بِالْمَاءِ قَالَ زَكَرِيَّا قَالَ مُصْعَبٌ وَنَسِيتُ الْعَاشِرَةَ إِلاَّ أَنْ تَكُونَ الْمَضْمَضَةَ  

The Apostle of Allaah ( sal Allaahu alayhi wa sallam ) said : The rinsing of mouth and snuffing up water in the nose are acts that bear the characteristics of fitrah (nature). He then narrated a similar tradition (as reported by Aishah), but he did not mention the words "letting the beard grow". He added the words "circumcision" and "sprinkling water on the private part of the body". He did not mention the words "cleansing oneself after easing". Abu Dawud said : A similar tradition has been reported on the authority of Ibn 'Abbas. He mentioned only five sunnahs all relating to the head, one of them being parting of the hair; it did not include wearing the beard. Abu Dawud said: The tradition as reported by Hammad has also been transmitted by Talq b. Habib , Mujahid, and Bakr b. 'Abd Allaah b. al-Muzani as their own statement ( not as a tradition from the Prophet, sal Allaahu alayhi wa sallam ).They did not mention the words "letting the beard grow". The version transmitted by Muhammad b. Abd Allaah b. Abi Maryam, Abu Salamah, and Abu Hurairah from the Prophet ( sal Allaahu alayhi wa sallam ) mentions the words "letting the beard grow". A similar tradition has been reported by Ibrahim al-Nakha'i. He mentioned the words "wearing the beard and circumcision."  

أَنَّ رَسُولَ اللَّهِ ﷺ قَالَ إِنَّ مِنَ الْفِطْرَةِ الْمَضْمَضَةَ وَالاِسْتِنْشَاقَ فَذَكَرَ نَحْوَهُ وَلَمْ يَذْكُرْ إِعْفَاءَ اللِّحْيَةِ وَزَادَ وَالْخِتَانَ قَالَ وَالاِنْتِضَاحَ وَلَمْ يَذْكُرِ انْتِقَاصَ الْمَاءِ يَعْنِي الاِسْتِنْجَاءَ