Quran 18:58

وَرَبُّكَ ٱلۡغَفُورُ ذُو ٱلرَّحۡمَةِ‌ۖ لَوۡ يُؤَاخِذُهُم بِمَا ڪَسَبُواْ لَعَجَّلَ لَهُمُ ٱلۡعَذَابَ‌ۚ بَل لَّهُم مَّوۡعِدٌ۬ لَّن يَجِدُواْ مِن دُونِهِۦ مَوۡٮِٕلاً۬ ٥٨

Yet, your Lord is the Forgiver, full of mercy. If He called them to account for their deeds, He would annihilate them right there and then. Instead, He gives them a respite until a specific, predetermined time; then they can never escape.