حَدَّثَنَا الْقَعْنَبِيُّ، حَدَّثَنَا عَبْدُ الْعَزِيزِ، عَنْ عَلْقَمَةَ، عَنْ أُمِّهِ، عَنْ عَائِشَةَ، أَنَّهَا قَالَتْ كُنْتُ أُحِبُّ أَنْ أَدْخُلَ الْبَيْتَ فَأُصَلِّيَ فِيهِ فَأَخَذَ رَسُولُ اللَّهِ صلى الله عليه وسلم بِيَدِي فَأَدْخَلَنِي فِي الْحِجْرِ فَقَالَ ‏"‏صَلِّي فِي الْحِجْرِ إِذَا أَرَدْتِ دُخُولَ الْبَيْتِ فَإِنَّمَا هُوَ قِطْعَةٌ مِنَ الْبَيْتِ فَإِنَّ قَوْمَكِ اقْتَصَرُوا حِينَ بَنَوُا الْكَعْبَةَ فَأَخْرَجُوهُ مِنَ الْبَيْتِ ‏"

Narrated Aisha, Ummul Mu'minin

I liked to enter the House and pray therein. The Messenger of Allah (ﷺ) took me by the hand and admitted me into al-Hijr, and said, "Pray in al-Hijr if you want to enter the House, for it is a part of the House. Your people shortened it when they built the Ka'bah and took it out of the House."