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."

أَخْبَرَنَا أَحْمَدُ بْنُ سُلَيْمَانَ، قَالَ حَدَّثَنَا أَبُو نُعَيْمٍ، قَالَ حَدَّثَنَا سَيْفُ بْنُ سُلَيْمَانَ، قَالَ سَمِعْتُ مُجَاهِدًا، يَقُولُ أُتِيَ ابْنُ عُمَرَ فِي مَنْزِلِهِ فَقِيلَ هَذَا رَسُولُ اللَّهِ ﷺ قَدْ دَخَلَ الْكَعْبَةَ فَأَقْبَلْتُ فَأَجِدُ رَسُولَ اللَّهِ ﷺ قَدْ خَرَجَ وَأَجِدُ بِلاَلاً عَلَى الْبَابِ قَائِمًا فَقُلْتُ يَا بِلاَلُ أَصَلَّى رَسُولُ اللَّهِ ﷺ فِي الْكَعْبَةِ قَالَ نَعَمْ . قُلْتُ أَيْنَ قَالَ مَا بَيْنَ هَاتَيْنِ الأُسْطُوَانَتَيْنِ رَكْعَتَيْنِ ثُمَّ خَرَجَ فَصَلَّى رَكْعَتَيْنِ فِي وَجْهِ الْكَعْبَةِ .