The Messenger of Allah ﷺ entered Mecca from its upper side and left from its lower side.
حدثنا سفيان عن هشام عن أبيه
أن رسول الله ﷺ دخل مكة من أعلى مكة وخرج من أسفلها
Its isnad is sahih. Bukhari 3/437 no. 1577, Muslim 2/918 no. 1257, Abu Dawud 2/174 no. 1868, and Tirmidhi 2/230 no. 853 all narrated it, and Tirmidhi said, hasan sahih, all of them in the chapter on Hajj.