Hazrat Abu Burdah bin Niyar (may Allah be pleased with him) slaughtered his animal before the Eid prayer. He said, "O Messenger of Allah! I have already slaughtered my animal." The Noble Prophet (peace and blessings be upon him) said to him, "Sacrifice another animal in its place." He said, "O Messenger of Allah! Now I only have a six-month-old lamb, which is better than a year-old animal." The Noble Prophet (peace and blessings be upon him) said, "Slaughter it in its place, but no one else besides you is permitted to do so."
Hadith Referenceمسند احمد / أول مسند الكوفيين / 18691