“I
was present on Adha day with the Messenger of Allah (ﷺ), and
some
people slaughtered before the prayer. The Prophet (ﷺ) said:
‘Whoever among you has slaughtered before the prayer, let him
repeat
his sacrifice, and whoever has not, let him offer his
sacrifice in the
Name of Allah.’”
Sunan Ibn Majah Book 26, Hadith 33