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

Ibn ‘Umar said that God’s messenger had his head shaved at the Farewell Pilgrimage, as did some of his companions, but some had their hair clipped. Bukhari and Muslim.