وَإِذ تَأَذَّنَ رَبُّكَ لَيَبعَثَنَّ عَلَيهِم إِلىٰ يَومِ القِيامَةِ مَن يَسومُهُم سوءَ العَذابِ ۗ إِنَّ رَبَّكَ لَسَريعُ العِقابِ ۖ وَإِنَّهُ لَغَفورٌ رَحيمٌ

Your Lord declared that He would send against them, until the Day of Resurrection, those who will inflict terrible suffering on them. Your Lord is swift in penalty; but He is also Forgiving, Most Merciful.