Sahih Muslim 6043
The Book of Virtues
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 .
Anas reported:I saw when the Messenger of Allah (ﷺ) 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
Text from the public-domain hadith-api dataset. Numbering follows that dataset and can differ by a few from some printed editions — check the wording, not only the number.