The Prophet ﷺ said, "No one should eat from the meat of his sacrifice beyond three days."
عن النبي ﷺ أنه قال: لا يأكل أحد من لحم أضحيته فوق ثلاثة أيام.
Muslim narrated it in the Chapter on Sacrifices (26:1970) via Layth (that is, Ibn Saad) from Nafi, from Ibn Umar, who mentioned it.