Abu Huraira reported: The Prophet, peace and blessings be upon him, said, “Five acts are a part of natural instinct: circumcision, shaving pubic hair, plucking hair from the armpits, shortening the moustache, and clipping the nails.”
Source: Ṣaḥīḥ al-Bukhārī 5939, Ṣaḥīḥ Muslim 257
Grade: Muttafaqun Alayhi (authenticity agreed upon) according to Al-Bukhari and Muslim
Yunus ibn Abdul ‘Ala reported: Ientered the home of Al-Shafi’i, may Allah have mercy on him, and with him was a barber shaving his armpits. Al-Shafi’i said, “I know the Sunnah is to pluck them, but I am not strong enough to endure the pain.”
Source: Sharḥ al-Nawawī ‘alá Ṣaḥīḥ Muslim 257
عَنْ أَبِي هُرَيْرَةَ رَضِيَ اللَّهُ عَنْهُ عَنْ النَّبِيِّ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ قَالَ الْفِطْرَةُ خَمْسٌ الْخِتَانُ وَالِاسْتِحْدَادُ وَنَتْفُ الْإِبْطِ وَقَصُّ الشَّارِبِ وَتَقْلِيمُ الْأَظْفَارِ
5939 صحيح البخاري كتاب الاستئذان باب الختان بعد الكبر ونتف الإبط
257 صحيح مسلم كتاب الطهارة باب خصال الفطرة
عَنْ يُونُسَ بْنِ عَبْدِ الْأَعْلَى قَالَ دَخَلْتُ عَلَى الشَّافِعِيِّ رَحِمَهُ اللَّهُ وَعِنْدَهُ الْمُزَيِّنُ يَحْلِقُ إِبْطَهُ فَقَالَ الشَّافِعِيُّ عَلِمْتُ أَنَّ السُّنَّةَ النَّتْفُ وَلَكِنْ لَا أَقْوَى عَلَى الْوَجَعِ
257 شرح النووي على مسلم