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."
Sahih al-Bukhari Book 25, Hadith 199
← Previous Hadith I heard `Aisha saying, "We set out (from Medina) along with Allah's Messenger (ﷺ) five days before the end of Dhul-Qa'da with the intention of performing Hajj only. When we approached Mecca, Allah's Apostle ordered those who had no Hadi along with them to finish the lhram after performing Tawaf of the Ka`ba, (Safa and Marwa). `Aisha added, "Beef was brought to us on the Day of Nahr and I said, 'What is this?' Somebody said, 'The Prophet (ﷺ) has slaughtered (cows) on behalf of his wives.' "

Sahih al-Bukhari Book 25, Hadith 198 Next Hadith → A man said to the Prophet (ﷺ) "I performed the Tawaf-al-Ifada before the Rami (throwing pebbles at the Jamra)." The Prophet (ﷺ) replied, "There is no harm." The man said, "I had my head shaved before slaughtering." The Prophet (ﷺ) replied, "There is no harm." He said, "I have slaughtered the Hadi before the Rami." The Prophet (ﷺ) replied, "There is no harm."

Sahih al-Bukhari Book 25, Hadith 200