﴿ وَإِنَّ رَبَّكَ لَهُوَ ٱلْعَزِيزُ ٱلرَّحِيمُ ﴾

“But, verily, thy Sustainer - He alone - is almighty, a dispenser of grace”

(And lo, thy Lord, He is indeed the Mighty) in retribution against them when He drowned them, (the Merciful) towards the believers when He saved them from drowning.