Sahih al-Bukhari 1811
Sahih al-Bukhari · Book 27: Pilgrims Prevented from Completing the Pilgrimage · The slaughtering before shaving the head (in case) one is prevented
Narrated Al-Miswar:
حَدَّثَنَا مَحْمُودٌ ، حَدَّثَنَا عَبْدُ الرَّزَّاقِ ، أَخْبَرَنَا مَعْمَرٌ ، عَنِ الزُّهْرِيِّ ، عَنْ عُرْوَةَ ، عَنِ الْمِسْوَرِ ـ رضى الله عنه ـ أَنَّ رَسُولَ اللَّهِ صلى الله عليه وسلم نَحَرَ قَبْلَ أَنْ يَحْلِقَ، وَأَمَرَ أَصْحَابَهُ بِذَلِكَ.
Allah's Messenger (ﷺ) slaughtered (the Hadi) before he had his head shaved and then he ordered his Companions to do the same.