Sahih Bukhari Volume 2, Book 26, Hadith Number 684.

Narated By ‘Abdullah bin ‘Umar  : When Allah’s Apostle performed Tawaf of the Ka’ba for Hajj or ‘Umra, he used to do Ramal during the first three rounds, and in the last four rounds he used to walk; then after the Tawaf he used to offer two Rakat and then performed Tawaf between Safa and Marwa.