It was narrated from Aswad bin Qais that he heard Jundub Al-Bajali say: “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.’”
Source: sunnah.com
Other translations
Arabic
حَدَّثَنَا هِشَامُ بْنُ عَمَّارٍ، حَدَّثَنَا سُفْيَانُ بْنُ عُيَيْنَةَ، عَنِ الأَسْوَدِ بْنِ قَيْسٍ، عَنْ جُنْدَبٍ الْبَجَلِيِّ، أَنَّهُ سَمِعَهُ يَقُولُ شَهِدْتُ الأَضْحَى مَعَ رَسُولِ اللَّهِ ـ صلى الله عليه وسلم ـ فَذَبَحَ أُنَاسٌ قَبْلَ الصَّلاَةِ فَقَالَ النَّبِيُّ ـ صلى الله عليه وسلم ـ " مَنْ كَانَ ذَبَحَ مِنْكُمْ قَبْلَ الصَّلاَةِ فَلْيُعِدْ أُضْحِيَّتَهُ وَمَنْ لاَ فَلْيَذْبَحْ عَلَى اسْمِ اللَّهِ " .
sunnah.com