Sahih al-Bukhari 5500
Narrated Jundub bin Sufyan Al-Bajali:
Once during the lifetime of Allah's Messenger (ﷺ) we offered some animals as sacrifices. Some people 
slaughtered their sacrifices before the (Id) prayer, so when the Prophet (ﷺ) finished his prayer, he saw that 
they had slaughtered their sacrifices before the prayer. He said, "Whoever has slaughtered (his 
sacrifice) before the prayer, should slaughter (another sacrifice) in lieu of it; and whoever has not yet 
slaughtered it till we have prayed; should slaughter (it) by mentioning Allah's Name."
حَدَّثَنَا قُتَيْبَةُ، حَدَّثَنَا أَبُو عَوَانَةَ، عَنِ الأَسْوَدِ بْنِ قَيْسٍ، عَنْ جُنْدَبِ بْنِ سُفْيَانَ الْبَجَلِيِّ، قَالَ ضَحَّيْنَا مَعَ رَسُولِ اللَّهِ صلى الله عليه وسلم أُضْحِيَّةً ذَاتَ يَوْمٍ فَإِذَا أُنَاسٌ قَدْ ذَبَحُوا ضَحَايَاهُمْ قَبْلَ الصَّلاَةِ فَلَمَّا انْصَرَفَ رَآهُمُ النَّبِيُّ صلى الله عليه وسلم أَنَّهُمْ قَدْ ذَبَحُوا قَبْلَ الصَّلاَةِ فَقَالَ ‏
"‏ مَنْ ذَبَحَ قَبْلَ الصَّلاَةِ فَلْيَذْبَحْ مَكَانَهَا أُخْرَى، وَمَنْ كَانَ لَمْ يَذْبَحْ حَتَّى صَلَّيْنَا فَلْيَذْبَحْ عَلَى اسْمِ اللَّهِ ‏"‏‏.‏