Ata'a bin al-Sa'ib al-Thaqifi عطاء بن السائب الثقفي · Chapters on Sacrifices

“I was present on Adha day with the Messenger of Allah (ﷺ), and some people slaughtered before the prayer. The Prophet (ﷺ) said: ‘Whoever among you has slaughtered before the prayer, let him repeat his sacrifice, and whoever has not, let him offer his sacrifice in the Name of Allah.’”