Sahih al-Bukhari 504
صحيح البخاري#504SahihNarrated Ibn `Umar:The Prophet (ﷺ) entered the Ka`ba along with Usama bin Zaid, `Uthman bin Talha and Bilal and remained there for a long time. When they came out, I was the first man to enter the Ka`ba. I asked Bilal "Where did the Prophet (ﷺ) pray?" Bilal replied, "Between the two front 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 al-Bukhari is accepted as Sahih (authentic) by the established status of the book.
In-book reference: 8:151