The Quran

Preface

وَالَّذينَ كَسَبُوا السَّيِّئَاتِ جَزاءُ سَيِّئَةٍ بِمِثلِها وَتَرهَقُهُم ذِلَّةٌ ۖ ما لَهُم مِنَ اللَّهِ مِن عاصِمٍ ۖ كَأَنَّما أُغشِيَت وُجوهُهُم قِطَعًا مِنَ اللَّيلِ مُظلِمًا ۚ أُولٰئِكَ أَصحابُ النّارِ ۖ هُم فيها خالِدونَ

Yusuf Ali

But those who have earned evil will have a reward of like evil:¹ ignominy will cover their (faces): No defender will they have from (the wrath of) God. Their faces will be covered, as it were, with pieces from the depth of the darkness² of night: they are companions of the Fire: they will abide therein (for aye)!

Note that the evil reward is for those who have “earned” evil, i.e., brought it on themselves by the deliberate choice of evil. Further, in the justice of God, they will be requited with evil similar to, and not greater in quantity or intensity, than the evil they had done - unlike the good, who, in God’s generosity, get a reward far greater than anything they have earned or could possibly earn.
Night is the negation of Light and metaphorically of joy and felicity. The intensive is indicated by “the depth of the darkness of Night.”