Sahih Muslim 3047
صحيح مسلم#3047SahihNafi' reported that Abdullah (b. 'Umar) informed him that Allah's Messenger (ﷺ) turned his face to the two hillocks which intervened between him and the long mountain by the side of the Ka'ba, and the mosque which had been built there was thus on the left of the hillock. Allah's Messenger's (ﷺ) place of prayer was lower than the black hillock, at a distance of ten cubits or near it. He (ﷺ) would then observe prayer facing these two hillocks of the long mountain that is intervening between you and the Ka'ba
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: 15:253