Hadithcore
Sahih Muslim, 1303
sahih

Yahya b. al-Husain reported on the authority of his grandfather that Allah's Messenger (ﷺ) invoked blessing on the occasion of the Farewell Pilgrimage three times for those who got their heads shaved and once for those who got their hair clipped. In the narration transmitted by Waki' there is no mention of the Farewell Pilgrimage.

حَدَّثَنَا أَبُو بَكْرِ بْنُ أَبِي شَيْبَةَ، حَدَّثَنَا وَكِيعٌ، وَأَبُو دَاوُدَ الطَّيَالِسِيُّ عَنْ شُعْبَةَ، عَنْ يَحْيَى بْنِ الْحُصَيْنِ، عَنْ جَدَّتِهِ، أَنَّهَا سَمِعَتِ النَّبِيَّ صلى الله عليه وسلم فِي حَجَّةِ الْوَدَاعِ دَعَا لِلْمُحَلِّقِينَ ثَلاَثًا وَلِلْمُقَصِّرِينَ مَرَّةً ‏.‏ وَلَمْ يَقُلْ وَكِيعٌ فِي حَجَّةِ الْوَدَاعِ ‏.‏

References2 variants
In-Book Reference
Book 15, Hadith 354
USC-MSA web (English) reference
Book 7, Hadith 2989 (deprecated numbering scheme)