It wasnarrated from 'Uwaimir bin Ashqar that he slaughtered beforetheprayer, and he mentioned that to the Prophet (ﷺ) who said:
"Repeatyour sacrifice." (ES)
English reference (ES): Vol. 4, Book 26, Hadith 3153 (ES)
Arabic reference (ES): Book 26, Hadith 3273 (ES)