Sahih Muslim 5082
صحيح مسلم#5082SahihJabir reported Allah's Messenger (ﷺ) as saying:Sacrifice only a grown-up animal, unless it is difficult for you, in which case sacrifice a ram (of even less than a year, but more than six months' age)
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: 35:19