Sahih Muslim , Hadith 2325 ⓘ
Anas reported: I saw when the Messenger of Allah got his hair cut by the barber, his Companions came round him and they eagerly wanted that no hair should fall but in the hand of a person.
حَدَّثَنَا مُحَمَّدُ بْنُ رَافِعٍ، حَدَّثَنَا أَبُو النَّضْرِ، حَدَّثَنَا سُلَيْمَانُ، عَنْ ثَابِتٍ، عَنْ أَنَسٍ، قَالَ لَقَدْ رَأَيْتُ رَسُولَ اللَّهِ صلى الله عليه وسلم وَالْحَلاَّقُ يَحْلِقُهُ وَأَطَافَ بِهِ أَصْحَابُهُ فَمَا يُرِيدُونَ أَنْ تَقَعَ شَعْرَةٌ إِلاَّ فِي يَدِ رَجُلٍ .
also referenced under: Book 43, Hadith 101 (In-Book) & Book 30, Hadith 5750 (USC-MSA)