Sunan An-Nasa'i

Some one came to Ibn Umar in his house and said:The Messenger of Allah has entered the Kabah."" So Ibn Umar said, I (Ibn Umar) came and found that the Messenger of Allah had come out, and I found Bilal standing at the door. I said: ""O Bilal, did the Messenger of Allah pray inside the Kabah?' He said: ""Ues."" I said: ""Where>"" He said: ""Between these two columns, two Rakahs. Then he came out and prayed two Rakahs in front of the Kabah