Surah Ar-Rum — Ayah 5 (30:5)

English translation (Saheeh International)

In the victory of Allāh.¹ He gives victory to whom He wills, and He is the Exalted in Might, the Merciful.

1. - i.e., the victory given by Allāh to a people of the Scripture (Christians) over the Magians of Persia.

Brief commentary

They will be happy because of the help of Allah being with the Romans due to them being the people of the book. Allah helps whoever He wishes against whoever He wishes; He is the Almighty who cannot be overcome, the Merciful towards His believing servants.