Sahih Bukhari Volume 2, Book 20, Hadith Number 187.

Narated By Yahya bin Ishaq : I heard Anas saying, “We travelled with the Prophet from Medina to Mecca and offered two Rakat (for every prayer) till we returned to Medina.” I said, “Did you stay for a while in Mecca?” He replied, “We stayed in Mecca for ten days.”