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 ﷺ يَوْمَ النَّحْرِ فَقَالَ " مَنْ ذَبَحَ قَبْلَ أَنْ يُصَلِّيَ فَلْيُعِدْ مَكَانَهَا أُخْرَى، وَمَنْ لَمْ يَذْبَحْ فَلْيَذْبَحْ ".