Full Sharh — Sahih Muslim 5065
وَحَدَّثَنَا أَبُو بَكْرِ بْنُ أَبِي شَيْبَةَ، حَدَّثَنَا أَبُو الأَحْوَصِ، سَلاَّمُ بْنُ سُلَيْمٍ عَنِ الأَسْوَدِ، بْنِ قَيْسٍ عَنْ جُنْدَبِ بْنِ سُفْيَانَ، قَالَ شَهِدْتُ الأَضْحَى مَعَ رَسُولِ اللَّهِ صلى الله عليه وسلم فَلَمَّا قَضَى صَلاَتَهُ بِالنَّاسِ نَظَرَ إِلَى غَنَمٍ قَدْ ذُبِحَتْ فَقَالَ " مَنْ ذَبَحَ قَبْلَ الصَّلاَةِ فَلْيَذْبَحْ شَاةً مَكَانَهَا وَمَنْ لَمْ يَكُنْ ذَبَحَ فَلْيَذْبَحْ عَلَى اسْمِ اللَّهِ " .
English Translation
Jundab b. Sufyan reported:I was with Allah's Messenger (ﷺ) (on the occasion) of 'Id al-Adha. After he had completed the prayer with people, he found that the goats had been slaughtered, whereupon he said: He who slaughtered sacrificial animal before the prayer should slaughter a goat (again) in its stead and he who has not slaughtered he should slaughter it by reciting the name of Allah
Source
Sahih Muslim(صحيح مسلم)
The Book of Sacrifices
Hadith Number
5065