Narrated Al-Bara' bin `Azib: An uncle of mine called Abu Burda, slaughtered his sacrifice before the `Id prayer. So Allah's Messenger (ﷺ) said to him, "Your (slaughtered) sheep was just mutton (not a sacrifice)." Abu Burda said, "O Allah's Messenger (ﷺ) ! I have got a domestic kid goat." The Prophet (ﷺ) said, "Slaughter it (as a sacrifice) but it will not be permissible for anybody other than you" The Prophet (ﷺ) added, "Whoever slaughtered his sacrifice before the (`Id) prayer, he only slaughtered for himself, and whoever slaughtered it after the prayer, he offered his sacrifice properly and followed the tradition of the Muslims."
