Pilgrimmage (Hajj)
Bukhari :: Book 2 :: Volume 26 :: Hadith 697
Narrated Ibn Abbas:
Allah's Apostle performed Tawaf (of the Kaba) ending a camel (at that time the Prophet had 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."