Sahih al-Bukhari, Hadith 5562 ⓘ
Narrated Jundab bin Sufyan Al-Bajali: I witnessed the Prophet 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."
حَدَّثَنَا آدَمُ، حَدَّثَنَا شُعْبَةُ، حَدَّثَنَا الأَسْوَدُ بْنُ قَيْسٍ، سَمِعْتُ جُنْدَبَ بْنَ سُفْيَانَ الْبَجَلِيَّ، قَالَ شَهِدْتُ النَّبِيَّ صلى الله عليه وسلم يَوْمَ النَّحْرِ فَقَالَ " مَنْ ذَبَحَ قَبْلَ أَنْ يُصَلِّيَ فَلْيُعِدْ مَكَانَهَا أُخْرَى، وَمَنْ لَمْ يَذْبَحْ فَلْيَذْبَحْ " .
also referenced under: Book 73, Hadith 18 (In-Book) & Volume 7, Book 68, Hadith 469 (USC-MSA)