Maliks Muwatta Book 20, Hadith Number 106.
Section : Concerning Building the Kaba.
Yahya related to me from Malik from Hisham ibn Urwa from his father that A’isha, umm al-muminin, said, “I do not mind whether I pray in the Hijr or in the House.” (i.e. praying in the Hijr is the same as praying in the House).