Regret and acknowledgment of wrongdoing

وَلَئِن مَّسَّتْهُمْ نَفْحَةٌ مِّنْ عَذَابِ رَبِّكَ لَيَقُولُنَّ يَـٰوَيْلَنَآ إِنَّا كُنَّا ظَـٰلِمِينَ

And if [as much as] a whiff of the punishment of your Lord should touch them, they would surely say, "O woe to us! Indeed, we have been wrongdoers."