From Sahih Bukhari (Hadith 1632):
Narrated Ibn `Abbas:Allah's Messenger (ﷺ) performed Tawaf (of the Ka`ba) riding a camel (at that time the Prophet (ﷺ) had a foot injury). Whenever he came to the Corner (having the Black Stone) he would point out towards it with a thing in his hand and say, "Allahu-Akbar
Reference: Bukhari 1632