Sahih Muslim 3230
صحيح مسلم#3230SahihIbn Umar (Allah be pleased with them) reported that Allah's Messenger (may peace, be upon him) entered the Ka'ba. Usama, Bilal and 'Uthman b. Talha, the keeper (of the Ka'ba), were along with him. He closed the door and stayed in it for some time. Ibn 'Umar (Allah be pleased with them) said:I asked Bilal as he came out what Allah's Messenger (ﷺ) had done there. He said: He prayed there in (such a position) that two pillars were on his left side, one pillar on his right, and three pillars were behind him, and the House at that time was resting on six pillars
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: 15:434