I saw Messenger of Allah ﷺ entering the Ka'ba, and Usama b. Zaid, Bilal and 'Uthman b. Talha were along with him, but none (else) entered therein along with them. Then the door was closed for them from within. 'Abdullah b. Umar (Allah be pleased with them) said: Bilal and Uthman b. Talha informed me that Messenger of Allah ﷺ observed prayer in the interior of the Ka'ba between the two Yemenite pillars.
رَأَيْتُ رَسُولَ اللَّهِ ﷺ دَخَلَ الْكَعْبَةَ هُوَ وَأُسَامَةُ بْنُ زَيْدٍ وَبِلاَلٌ وَعُثْمَانُ بْنُ طَلْحَةَ وَلَمْ يَدْخُلْهَا مَعَهُمْ أَحَدٌ ثُمَّ أُغْلِقَتْ عَلَيْهِمْ قَالَ عَبْدُ اللَّهِ بْنُ عُمَرَ فَأَخْبَرَنِي بِلاَلٌ أَوْ عُثْمَانُ بْنُ طَلْحَةَ أَنَّ رَسُولَ اللَّهِ ﷺ صَلَّى فِي جَوْفِ الْكَعْبَةِ بَيْنَ الْعَمُودَيْنِ الْيَمَانِيَيْنِ