(17) باب قَوْلِ النَّبِيِّ صلى الله عليه وسلم " فَلْيَذْبَحْ عَلَى اسْمِ اللَّهِ ".
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."
Reference: Sahih al-Bukhari 5500
In-book reference: Book 72, Hadith 26
USC-MSA web (English) reference(deprecated numbering scheme): Vol. 7, Book 67, Hadith 408