It wasnarrated from Aswad bin Qais that he heard Jundub Al-Bajalisay:
"Iwas present on Adha day with the Messenger of Allah (ﷺ), andsomepeople slaughtered before the prayer. The Prophet (ﷺ) said:'Whoever among you has slaughtered before the prayer, let himrepeathis sacrifice, and whoever has not, let him offer hissacrifice in theName of Allah.'" (TR)
English reference (TR): Vol. 4, Book 26, Hadith 3152 (TR)
Arabic reference (TR): Book 26, Hadith 3272 (TR)