“I was present on Adha day with the Messenger of Allah ﷺ, and some people slaughtered before the prayer. The Prophet ﷺ said: ‘Whoever among you has slaughtered before the prayer, let him repeat his sacrifice, and whoever has not, let him offer his sacrifice in the Name of Allah.’”
أَنَّهُ سَمِعَهُ يَقُولُ شَهِدْتُ الأَضْحَى مَعَ رَسُولِ اللَّهِ ﷺ فَذَبَحَ أُنَاسٌ قَبْلَ الصَّلاَةِ فَقَالَ النَّبِيُّ ﷺ مَنْ كَانَ ذَبَحَ مِنْكُمْ قَبْلَ الصَّلاَةِ فَلْيُعِدْ أُضْحِيَّتَهُ وَمَنْ لاَ فَلْيَذْبَحْ عَلَى اسْمِ اللَّهِ