Sahih Muslim 2632
صحيح مسلم#2632SahihUmm al-Fadl bint- al-Harith reported that some people argued about the fasting of the Messenger of Allah (ﷺ) on the day of 'Arafa. Some of them said that he had been fasting, whereas the others said that he had not been fasting. I sent a cup of milk to him while he was riding his camel at 'Arafa, and he drank it
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: 13:138