I witnessed the Prophet ﷺ on the Day of Nahr. He said, "Whoever slaughtered the sacrifice before offering the ʿId prayer, should slaughter another sacrifice in its place; and whoever has not slaughtered their sacrifice yet, should slaughter now."
شَهِدْتُ النَّبِيَّ ﷺ يَوْمَ النَّحْرِ فَقَالَ مَنْ ذَبَحَ قَبْلَ أَنْ يُصَلِّيَ فَلْيُعِدْ مَكَانَهَا أُخْرَى وَمَنْ لَمْ يَذْبَحْ فَلْيَذْبَحْ