عَنِ ابْنِ عُمَرَ: أَنَّ رَسُولَ اللَّهِ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ حَلَقَ رَأْسَهُ فِي حَجَّةِ الْوَدَاعِ وَأُنَاسٌ مِنْ أَصْحَابِهِ وَقَصَّرَ بَعْضُهُمْ

Ibn ‘Abbas said that Mu'awiya told him he had clipped some hair from the Prophet’s head at al-Marwa with a broad, iron arrowhead. Bukhari and Muslim.