Wallatheena saAAaw fee ayatina muAAajizeena ola-ika lahum AAathabun min rijzin aleem (surah Saba: 5)

Tafseer Tafheem-ul-Quran by Syed Abu-al-A'la Maududi

(34:5) As for those who worked against Our Signs in order to frustrate them, they shall suffer a painful chastisement. *8

Wallazeena sa`aw feee aayaatinaa mu`aajizeena ulaaa `ika lahum `azaabum mir irjzin aleem

*8) The above was an argument for the possibility of the Hereafter: this is an argument for its need ard necessity. It means: A time must come when the wicked should be requited for their wickedness and the righteous rewarded for their righteousness. Reason wants and justice demands that a worker of goodness should be rewarded and a worker of evil punished. Now when you see that in the present worldly life neither is an evildoer fully requited for his evil nor a worker of goodness for his goodness, rather there are opposite results of evil and goodness in most cases, you should admit that this necessary demand of both reason and justice must be fulfilled at some time in the future. Resurrection and the Hereafter will be the same time. It is not its coming but its not coming which is contrary to reason and against justice.
In this connection, another point becomes evident from the preceding verses. They tell that the result of faith and righteous acts is forgiveness and a bounteous provision, and for those who strive and act antagonistically in order to discredit and defeat Allah's Religion, there will be a torment of the worst kind. This makes it manifest that he who believes sincerely will not be deprived of forgiveness even though he may not get a bounteous provision owing to some flaw or weakness in his deeds. And the one who is a disbeliever but who dces not adopt an attitude of enmity and antagonism towards the true Faith, will not be able to avoid the torment but he will be saved from the worst torment.