Sahih Muslim 1305
Sahih Muslim · Book 15: The Book of Pilgrimage · The Sunnah on the day of sacrifice is to stone the Jamrah, then offer the sacrifice, then shave the head, and shaving should be started on the right side of the head
Anas b. Malik (Allah be pleased with him) reported:
وَحَدَّثَنَا ابْنُ أَبِي عُمَرَ ، حَدَّثَنَا سُفْيَانُ ، سَمِعْتُ هِشَامَ بْنَ حَسَّانَ ، يُخْبِرُ عَنِ ابْنِ سِيرِينَ ، عَنْ أَنَسِ بْنِ مَالِكٍ ، قَالَ لَمَّا رَمَى رَسُولُ اللَّهِ صلى الله عليه وسلم الْجَمْرَةَ وَنَحَرَ نُسُكَهُ وَحَلَقَ نَاوَلَ الْحَالِقَ شِقَّهُ الأَيْمَنَ فَحَلَقَهُ ثُمَّ دَعَا أَبَا طَلْحَةَ الأَنْصَارِيَّ فَأَعْطَاهُ إِيَّاهُ ثُمَّ نَاوَلَهُ الشِّقَّ الأَيْسَرَ فَقَالَ " احْلِقْ " . فَحَلَقَهُ فَأَعْطَاهُ أَبَا طَلْحَةَ فَقَالَ " اقْسِمْهُ بَيْنَ النَّاسِ " .
When Allah's Messenger (ﷺ) had thrown pebbles at the Jamra and had sacrificed the animal, he turned (the right side) of his head towards the barber, and i. e shaved it. He then called Abu Talha al-Ansari and gave it to him. He then turned his left side and asked him (the barber) to shave. And he (the barber) shaved. and gave it to Abu Talha and told him to distribute it amongst the people.