Surah Al-Hijr — Ayah 50 (15:50)
وَأَنَّ عَذَابِي هُوَ ٱلۡعَذَابُ ٱلۡأَلِيمُ ٥٠
English translation (Saheeh International)
And that it is My punishment which is the painful punishment.
Brief commentary
And inform them that My punishment is the severe punishment, so they should repent to Me so they can receive My forgiveness and be safe from My punishment.