Hazrat Anas bin Malik, may Allah be pleased with him, narrated that the Holy Prophet, peace and blessings of Allah be upon him, said:
“Whoever slaughtered the sacrifice before the prayer, he just slaughtered it for himself, and whoever slaughtered it after the prayer, he slaughtered it at the right time and followed the tradition of the Muslims.” Allah’s Messengersa said, “But you do not do that with pride.”
(Sahih al-Bukhari, Kitab al-Adha)