Chapter 16: The Book of Pilgrimage
' Abdullah reported that Allah' s Messenger (ﷺ) got his head shaved (after slaughtering the sacrificial animal on the 10th of Dhu' l-Hijja), and so did a group of Companions, while some of them got their hair clipped. Abdullah said: Allah' s Messenger (may peace' be upon him) observed once or twice: " May Allah have mercy upon those who get their heads shaved." And he also said: " Upon those too who got their hair clipped."
Sahih Muslim 1301a