ENOfficial
Al-Miswar b. Makhrama said that God’s messenger sacrificed before having his head shaved and ordered his companions to do the same. Bukhari transmitted it.
Source: sunnah.com
Other translations
Arabic
وَعَنِ الْمِسْوَرِ بْنِ مَخْرَمَةَ قَالَ: إِنَّ رَسُولَ اللَّهِ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ نَحَرَ قَبْلَ أَنْ يَحْلِقَ وَأَمَرَ أَصْحَابَهُ بِذَلِكَ. رَوَاهُ الْبُخَارِيُّ
sunnah.com