بِسْمِ اللَّهِ وَاللَّهُ أَكْبَرُ
Transliteration
Bismillahi wallahu akbar
English meaning
In the name of Allah, and Allah is the Greatest.
When is it recited?
Recited each time passing the Black Stone during tawaf.
Source
Bayhaqi, 5/79; Narration of Ibn Abbas (RA)