سُنَنُ ابْنِ مَاجَهْ
Sunan Ibn Majah 292
The Book of Purification and its Sunnah
The Fitrah (natural inclination of man)
حَدَّثَنَا أَبُو بَكْرِ بْنُ أَبِي شَيْبَةَ، حَدَّثَنَا سُفْيَانُ بْنُ عُيَيْنَةَ، عَنِ الزُّهْرِيِّ، عَنْ سَعِيدِ بْنِ الْمُسَيَّبِ، عَنْ أَبِي هُرَيْرَةَ، قَالَ قَالَ رَسُولُ اللَّهِ ـ صلى الله عليه وسلم ـ الْفِطْرَةُ خَمْسٌ - أَوْ خَمْسٌ مِنَ الْفِطْرَةِ - الْخِتَانُ وَالاِسْتِحْدَادُ وَتَقْلِيمُ الأَظْفَارِ وَنَتْفُ الإِبِطِ وَقَصُّ الشَّارِبِ .
It was narrated that Abu Hurairah said: "The Messenger of Allah said: 'The deeds connected to the Fitrah are five (or five things are connected to the Fitrah): circumcision, shaving the pubic hairs, clipping the nails, plucking the armpit hairs and trimming the mustache.'"
Sunan Ibn Majah, 292Sahih (Darussalam)