I witnessed the Prophet (ﷺ) on the Day of Nahr. He said, "Whoever slaughtered the sacrifice before offering the `Id prayer, should slaughter another sacrifice in its place; and whoever has not slaughtered their sacrifice yet, should slaughter now."
Sahih al-Bukhari Book 73, Hadith 18
← Previous Hadith The Prophet (ﷺ) said, "Whoever slaughtered the sacrifice before the `Id prayer, should repeat it (slaughter another one)." A man said "This is the day on which meat is desired." Then he mentioned the need of his neighbors (for meat) and the Prophet (ﷺ) seemed to accept his excuse. The man said, "I have a Jadha'a which is to me better than two sheep." The Prophet (ﷺ) allowed him (to slaughter it as a sacrifice). But I do not know whether this permission was general for all Muslims or not. The Prophet (ﷺ) then went towards two rams and slaughtered them, and the people went towards their sheep and slaughtered them.

Sahih al-Bukhari Book 73, Hadith 17 Next Hadith → One day Allah's Messenger (ﷺ) offered the `Id prayer and said, "Whoever offers our prayer and faces our Qibla should not slaughter the sacrifice till he finishes the `Id prayer." Abu Burda bin Niyar got up and said, "O Allah's Messenger (ﷺ)! I have already done it. The Prophet (ﷺ) said, "That is something you have done before its due time." Abu Burda said, "I have a Jadha'a which is better than two old sheep; shall I slaughter it?" The Prophet (ﷺ) said, "Yes, but it will not be sufficient for anyone after you."

Sahih al-Bukhari Book 73, Hadith 19