18.58
Abbas - Tanwîr al-Miqbâs min Tafsîr Ibn ‘Abbâs
(Thy Lord is the Forgiver, Full of Mercy) in that He defers His chastisement. (If He took them to task (now) for what they earn) for their idolatry, (He would hasten on the doom for them) in this worldly life; (but theirs is an appointed term) for their destruction (from which) from Allah's chastisement (they will find no escape) they will find no refuge.
And your Lord is the Forgiver Full of Mercy. Were He to take them to task in this world for what they have earned He would have hastened for them the chastisement therein; but they have a tryst which is the Day of Resurrection from which they will not find any escape any refuge.
The Worst People are Those Who turn away after being reminded
Allah says, `Who among My creatures does more wrong than one who is reminded of the signs of Allah then turns away from them,' i.e., ignores them and does not listen or pay attention to them.
وَنَسِىَ مَا قَدَّمَتْ يَدَاهُ
(forgetting what his hands have sent forth.) means, bad deeds and evil actions.
إِنَّا جَعَلْنَا عَلَى قُلُوبِهِمْ
(Truly, We have set over their hearts) means, the hearts of these people,
أَكِنَّةً
(Akinnah) means, coverings.
أَن يَفْقَهُوهُ
(lest they should understand this,) means, so that they will not understand this Qur'an and its clear Message
وَفِى ءَاذَانِهِمْ وَقْرًا
(and in their ears, deafness.) means that they will be deaf in an abstract way, to guidance.
(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:
(And these towns, We destroyed them when they did wrong.) This refers to earlier nations in times past; `We destroyed them because of their stubborn disbelief.'
وَجَعَلْنَا لِمَهْلِكِهِم مَّوْعِدًا
(And We appointed a fixed time for their destruction.) `We appointed for them a set time limit, not to be increased or decreased. The same applies to you, O ido- lators, so beware or what happened to them will happen to you too, for you have rejected the noblest Messenger and greatest Prophet, and you are not dearer to Us than them, so fear My punishment and wrath.'
18.58
Maududi - Sayyid Abul Ala Maududi - Tafhim al-Qur'an
This is to warn the foolish people that they should not be deluded by the respite that is given to them and presume that they will never be taken to task whatever they may go on doing. They forget that Allah gives them respite because He is Forgiving and Forbearing and does not punish the evil-doers on the spot, for His Mercy demands that the evil-doers should be given respite so that they may mend their ways.