Sahih Muslim 815
صحيح مسلم#815SahihIbn Wa'la al-Saba'i reported:I asked 'Abdullah b. 'Abbas saying: We are the inhabitants of the western regions. The Magians come to us with skins full of water and fat. He said: Drink. I said to him: Is it your own opinion? Ibn Abbas said: I heard the Messenger of Allah (ﷺ) say: Tanning purifies it (the skin)
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: 3:136