Sahih Muslim 5102
صحيح مسلم#5102SahihIbn 'Umar reported that Allah's Messenger (ﷺ) forbade that the flesh of sacrificial animals be eaten beyond three (days) Salim (son of Ibn Umar) said:Ibn 'Umar did not eat the flesh of the sacrificial animals beyond three (days). Ibn Abu 'Umar said:" Beyond three days
Scholarly Authentication
We show the most cautious grade (weakest-wins) as the overall label. Individual scholars graded it as follows:
Every narration in Sahih Muslim is accepted as Sahih (authentic) by the established status of the book.
In-book reference: 35:39