Sunan an-Nasa'i 2907
سنن النسائي#2907SahihIt was narrated that Ibn Umar said:"The Messenger of Allah entered the Kabah, and was about to come out, when I thought of something, so I came quickly and I found the Messenger of Allah coming out. I asked Bilal: Did the Messenger of Allah prayed inside the Kabah?' He said: 'Yes, two Rakahs between the two columns
Scholarly Authentication
We show the most cautious grade (weakest-wins) as the overall label. Individual scholars graded it as follows:
Abu GhuddahSahih
Al-AlbaniSahih
Zubair Ali ZaiIsnaad Sahih
In-book reference: 24:290