Surah Al Kahf Tafseer

وَرَبُّكَ الْغَفُورُ ذُو الرَّحْمَةِ

And your Lord is Most Forgiving, Owner of mercy.

means, `your Lord, O Muhammad, is forgiving and has great mercy.'

لَوْ يُوَاخِذُهُم بِمَا كَسَبُوا لَعَجَّلَ لَهُمُ الْعَذَابَ

Were He to call them to account for what they have earned, then surely, He would have hastened their punishment.

This is like the Ayah:

وَلَوْ يُوَاخِذُ اللَّهُ النَّاسَ بِمَا كَسَبُواْ مَا تَرَكَ عَلَى ظَهْرِهَا مِن دَابَّةٍ

And if Allah were to punish men for that which they earned, He would not leave a moving creature on the surface of the earth. (35:45)

وَإِنَّ رَبَّكَ لَذُو مَغْفِرَةٍ لِّلنَّاسِ عَلَى ظُلْمِهِمْ وَإِنَّ رَبَّكَ لَشَدِيدُ الْعِقَابِ

But verily, your Lord is full of forgiveness for mankind in spite of their wrongdoing. And verily, your Lord is (also) severe in punishment. (13:6)

And there are many Ayat which say the same thing.

Then Allah tells us that He is patient, He conceals faults and forgives sins. He may guide some of them from wrongdoing to true guidance, and whoever continues in his evil ways, then there will come to him a Day when infants will turn grey and every pregnant female will shed her load.

He says:

بَل لَّهُم مَّوْعِدٌ لَّن يَجِدُوا مِن دُونِهِ مَوْيِلً

But they have their appointed time, beyond which they will find no escape.

meaning, they will find no way out