Language:
كتاب الحج
25
Hajj (Pilgrimage)
(125)
Chapter: Slaughtering before having one’s head shaved
(125)
باب الذَّبْحِ قَبْلَ الْحَلْقِ

Narrated Ibn `Abbas:

The Prophet (ﷺ) was asked about a person who had his head shaved before slaughtering (his Hadi) (or other similar ceremonies of Hajj). He replied, "There is no harm, there is no harm."

حَدَّثَنَا مُحَمَّدُ بْنُ عَبْدِ اللَّهِ بْنِ حَوْشَبٍ، حَدَّثَنَا هُشَيْمٌ، أَخْبَرَنَا مَنْصُورٌ، عَنْ عَطَاءٍ، عَنِ ابْنِ عَبَّاسٍ ـ رضى الله عنهما ـ قَالَ سُئِلَ النَّبِيُّ صلى الله عليه وسلم عَمَّنْ حَلَقَ قَبْلَ أَنْ يَذْبَحَ وَنَحْوِهِ‏.‏ فَقَالَ ‏ "‏ لاَ حَرَجَ، لاَ حَرَجَ ‏"‏‏.‏
Reference : Sahih al-Bukhari 1721
In-book reference : Book 25, Hadith 199
USC-MSA web (English) reference : Vol. 2, Book 26, Hadith 779
  (deprecated numbering scheme)