Sahih Bukhari Volume 4, Book 52, Hadith Number 238.
Narated By Abdullah bin Umar : Whenever the Prophet returned from the Hajj or the ‘Umra or a Ghazwa, he would say Takbir thrice. Whenever he came upon a mountain path or wasteland, and then he would say, “None has the right to be worshipped but Allah, Alone Who has no partner. All the Kingdom belongs to Him and all the praises are for Him and He is Omnipotent. We are returning with repentance, worshipping, prostrating ourselves and praising our Lord. Allah fulfilled His Promise, granted victory to His slave and He Alone defeated all the clans.”