Dua for The Takbeer passing the black stone

Allaahu 'Akbar.

The Prophet (SAW) performed Tawaf riding a camel. Every time he passed the corner (containing the Black Stone), he would point to it with something that he was holding and say: Allaahu 'Akbar. (Allah is the Most Great)(The 'something' that was referred to in this Hadith was a cane.)