Narrated Al-Bara' bin `Azib
On the day of Nahr Allah's Messenger (ﷺ) delivered the Khutba after the `Id prayer and said, "Anyone who prayed like us and slaughtered the sacrifice like we did then he acted according to our (Nusuk) tradition of sacrificing, and whoever slaughtered the sacrifice before the prayer, then that was just mutton (i.e. not sacrifice)." Abu Burda bin Naiyar stood up and said, "O Allah's Messenger (ﷺ)! By Allah, I slaughtered my sacrifice before I offered the (Id) prayer and thought that today was the day of eating and drinking (nonalcoholic drinks) and so I made haste (in slaughtering) and ate and also fed my family and neighbors." Allah's Messenger (ﷺ) said, "That was just mutton (not a sacrifice)." Then Abu Burda said, "I have a young she-goat and no doubt, it is better than two sheep. Will that be sufficient as a sacrifice for me?" The Prophet (ﷺ) replied, "Yes. But it will not be sufficient for anyone else (as a sacrifice), after you."
Narrated Anas bin Malik
Allah's Messenger (ﷺ) offered the prayer on the day of Nahr and then delivered the Khutba and ordered that whoever had slaughtered his sacrifice before the prayer should repeat it, that is, should slaughter another sacrifice. Then a person from the Ansar stood up and said, "O Allah's Messenger (ﷺ)! because of my neighbors (he described them as being very needy or poor) I slaughtered before the prayer. I have a young she-goat which, in my opinion, is better than two sheep." The Prophet (ﷺ) gave him the permission for slaughtering it as a sacrifice.
Narrated Jundab
On the day of Nahr the Prophet (ﷺ) offered the prayer and delivered the Khutba and then slaughtered the sacrifice and said, "Anybody who slaughtered (his sacrifice) before the prayer should slaughter another animal in lieu of it, and the one who has not yet slaughtered should slaughter the sacrifice mentioning Allah's name on it."