(57) باب مَنْ حَلَقَ قَبْلَ النَّحْرِ أَوْ نَحَرَ قَبْلَ الرَّمْىِ
Adullah b. 'Amr (b. al-'As) (Allah be pleased with him) reported that a person came to Allah's Apostle (ﷺ) and said:
I got (my head) shaved before sacrificing the, animal, whereupon be (the Holy Prophet) said: Sacrifice the animal (now) ; there is no harm in it. He (the person said): I sacripced the animal before throwingpebbles. whereupon he said: Throw pebbles (now) ; there is no harm in it.
Reference: Sahih Muslim 1306 f
In-book reference: Book 15, Hadith 365
USC-MSA web (English) reference(deprecated numbering scheme): Book 7, Hadith 3000