Sahih Muslim Book 7, Hadith Number 2887.

Chapter : Excellence of entry into Mecca from the upper side and exit from it from the lower side, and entering the town from the side other than that from which one gets out.

‘Aisha (Allah be pleased with her) reported that when Allah’s Messenger may peace be upon him) came to Mecca he entered from its upper side and came out from its lower side.