وَيَسْتَعْجِلُونَكَ بِٱلسَّيِّئَةِ قَبْلَ ٱلْحَسَنَةِ وَقَدْ خَلَتْ مِن قَبْلِهِمُ ٱلْمَثُلَـٰتُ ۗ وَإِنَّ رَبَّكَ لَذُو مَغْفِرَةٍ لِّلنَّاسِ عَلَىٰ ظُلْمِهِمْ ۖ وَإِنَّ رَبَّكَ لَشَدِيدُ ٱلْعِقَابِ
Wa yasta'jiloonaka bis saiyi'ati qablal hasanati wa qad khalat min qablihimul masulaat; wa inna Rabbaka lazoo maghfiratil linnaasi 'alaa zulmihim wa inna Rabbaka lashadeedul 'iqaab
They ask you to bring on the punishment rather than any promised rewards, though there have been many examples before them––your Lord is full of forgiveness for people, despite their wrongdoing, but He is truly severe in punishment.
They urge you to hasten the harm before the good, though exemplary punishments have already passed before them. Your Lord is full of forgiveness for people despite their wrongdoing, and your Lord is severe in retribution.
Mercy is named first here, and named while the wrongdoing still stands: the Arabic gives forgiveness for people ʿalā ẓulmihim, over their wrong, with the wrong still in place. What they had demanded was the punishment, brought forward as a taunt, and the answer they get names forgiveness before it names severity. Both halves of the closing sentence open with the same phrase in Arabic, holding the two together in one hand.