It was narrated that Jundub bin Sufyan said: “I attended (the day of) sacrifice with the Messenger of Allah صلی اللہ علیہ وآلہ وسلم :. He led the people in prayer, then when he finished praying he saw some sheep that had been sacrificed. He said: ‘Whoever slaughtered (his sacrifice) before the prayer, let him slaughter a sheep in its place, and whoever has not slaughtered, let him offer a sacrifice in the name of Allah, the Mighty and Sublime.” (Sahih)