Sahih Bukhari Volume 1, Book 8, Hadith 505

حَدَّثَنَا عَبْدُ اللَّهِ بْنُ يُوسُفَ، قَالَ أَخْبَرَنَا مَالِكٌ، عَنْ نَافِعٍ، عَنْ عَبْدِ اللَّهِ بْنِ عُمَرَ، أَنَّ رَسُولَ اللَّهِ صلى الله عليه وسلم دَخَلَ الْكَعْبَةَ وَأُسَامَةُ بْنُ زَيْدٍ وَبِلاَلٌ وَعُثْمَانُ بْنُ طَلْحَةَ الْحَجَبِيُّ فَأَغْلَقَهَا عَلَيْهِ وَمَكَثَ فِيهَا، فَسَأَلْتُ بِلاَلاً حِينَ خَرَجَ مَا صَنَعَ النَّبِيُّ صلى الله عليه وسلم قَالَ جَعَلَ عَمُودًا عَنْ يَسَارِهِ، وَعَمُودًا عَنْ يَمِينِهِ، وَثَلاَثَةَ أَعْمِدَةٍ وَرَاءَهُ، وَكَانَ الْبَيْتُ يَوْمَئِذٍ عَلَى سِتَّةِ أَعْمِدَةٍ، ثُمَّ صَلَّى‏.‏ وَقَالَ لَنَا إِسْمَاعِيلُ حَدَّثَنِي مَالِكٌ وَقَالَ عَمُودَيْنِ عَنْ يَمِينِهِ

Narrated By Nafi' : 'Abdullah bin 'Umar said, "Allah's Apostle entered the Ka'ba along with Usama bin Zaid, Bilal and 'Uthman bin Talha Al-Hajabi and closed the door and stayed there for some time. I asked Bilal when he came out, 'What did the Prophet do?' He replied, 'He offered prayer with one pillar to his left and one to his right and three behind.' In those days the Ka'ba was supported by six pillars." Malik said: "There were two pillars on his (the Prophet's) right side."