Surah Fussilat — Ayah 41 (41:41)

English translation (Saheeh International)

Indeed, those who disbelieve in the message [i.e., the Qur’ān]¹ after it has come to them...² And indeed, it is a mighty³ Book.

1. i.e., reject it or prefer deviant interpretation.
2. The conclusion is understood to be "...will have earned an indescribable punishment."
3. Inimitable, resistant to attack, protected by Allāh.

Brief commentary

Indeed, those who disbelieved in the Qur’ān when it came to them from Allah will definitely be punished on the Day of Judgement.