Abu Dawud Book 4, Hadith Number 2023.

Narated By ‘Aisha, Ummul Mu’minin : I liked to enter the House (the Ka’bah) and pray therein. The Apostle of Allah (PBUH) caught me by hand and admitted me to al-Hijr. He then said: Pray in al-Hijr when you intend to enter the House (the Ka’bah), for it is a part of the House (the Ka’bah). Your people shortened it when they built the Ka’bah, and they took it out of the House.