It was narrated from ‘Abdullah bin ‘Amr that the Prophet ﷺ was asked about a man who slaughtered his sacrifice before shaving his head, or who shaved his head before slaughtering his sacrifice, and he said:
“There is no harm in that.”

حَدَّثَنَا عَلِيُّ بْنُ مُحَمَّدٍ، حَدَّثَنَا سُفْيَانُ بْنُ عُيَيْنَةَ، عَنِ الزُّهْرِيِّ، عَنْ عِيسَى بْنِ طَلْحَةَ، عَنْ عَبْدِ اللَّهِ بْنِ عَمْرٍو، أَنَّ النَّبِيَّ ـ ﷺ ـ سُئِلَ عَمَّنْ ذَبَحَ قَبْلَ أَنْ يَحْلِقَ أَوْ حَلَقَ قَبْلَ أَنْ يَذْبَحَ قَالَ " لاَ حَرَجَ " .