﴿ وَرَبُّكَ ٱلْغَفُورُ ذُو ٱلرَّحْمَةِ ۖ لَوْ يُؤَاخِذُهُم بِمَا كَسَبُوا۟ لَعَجَّلَ لَهُمُ ٱلْعَذَابَ ۚ بَل لَّهُم مَّوْعِدٌۭ لَّن يَجِدُوا۟ مِن دُونِهِۦ مَوْئِلًۭا ﴾

“Yet, [withal,] thy Sustainer is the Truly-Forgiving One, limitless in His grace. Were He to take them [at once] to task for whatever [wrong] they commit, He would indeed bring about their speedy punishment [then and there]: but nay, they have a time-limit beyond which they shall find no redemption”

Please check ayah 18:59 for complete tafsir.