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