Hadith #3039 (Sahih Muslim)
Book: The Book of Pilgrimage
Narrator(s): Abdullah bin 'Amir عبد الله بن عامر بن يزيد بن تميم
Grade: Sahih

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.

Source: https://parallelquran.com/hadith/sahih-muslim-3039/