The Messenger of Allah ﷺ shaved his head during the Farewell Pilgrimage.
حدثنا شجاع بن الوليد عن موسى بن عقبة عن نافع
أن رسول الله ﷺ حلق رأسه في حجة الوداع
Its isnad is sahih. Shuja bin Walid bin Qays Sakuni, his reliability was already established at 895, and we add here that Bukhari included his biography in Al-Kabir 2/2/262. Sakuni is with a fatha on the plain sin, a damma on the kaf, and ends with a nun, a designation derived from Sakun bin Ashras. The hadith is a repetition of 5623, and see also 6005.