Sahih Bukhari Volume 002, Book 026, Hadith Number 803.
Narated By 'Abdur-Rahman bin Yazid : 'Abdullah, did the Rami from the middle of the valley. So, I said, "O, Abu 'Abdur-Rahman! Some people do the Rami (of the Jamra) from above it (i.e. from the top of the valley)." He said, "By Him except whom none has the right to be worshipped, this is the place from where the one on whom Surat-al-Baqara was revealed (i.e. Allah's Apostle) did the Rami."