Sahih Bukhari Volume 002, Book 026, Hadith Number 653.
Narated By 'Aisha : (The wife of the Prophet) that Allah's Apostle said to her, "Do you know that when your people (Quraish) rebuilt the Ka'ba, they decreased it from its original foundation laid by Abraham?" I said, "O Allah's Apostle! Why don't you rebuild it on its original foundation laid by Abraham?" He replied, "Were it not for the fact that your people are close to the pre-lslamic Period of ignorance (i.e. they have recently become Muslims) I would have done so." The sub-narrator, 'Abdullah (bin 'Umar) stated: 'Aisha 'must have heard this from Allah's Apostle for in my opinion Allah's Apostle had not placed his hand over the two corners of the Ka'ba opposite Al-Hijr only because the Ka'ba was not rebuilt on its original foundations laid by Abraham.