(Zalzala) 99 : 1
بِسْمِ اللَّهِ الرَّحْمَٰنِ الرَّحِيمِ إِذَا زُلْزِلَتِ الْأَرْضُ زِلْزَالَهَا
When the earth will be shaken with her utmost quaking.
This verse reminds the occasion of shaking the earth completely with severe convulsions on the Doomsday. See explanation 89:21-22.