64. This is again an allusion to the war that was going on between Byzantium and Iran, which was telling on the whole of the Middle East. “What the hands of people have earned” means the wickedness and oppression and tyranny, which inevitably appear in human conduct and character as a result of adopting shirk and atheism and ignoring the Hereafter. “Perhaps they may return” means that Allah shows the evil consequences of some of the acts of men in this world before the punishment of the Hereafter so that they understand the reality, feel the error of their conjectures and turn to the righteous belief, which the Prophets of Allah have been presenting before man since the earliest times, and besides adopting which there is no other way of ordering human conduct on sound foundations. This subject has been presented at several places in the Quran, e.g. in (Surah At-Taubah: Ayat 126), (Surah Ar-Raad: Ayat 31), (Surah As-Sajdah: Ayat 21), (Surah At-Tur: Ayat 47).
65. That is, “The disastrous war between Byzantium and Iran is not a new thing of its kind. The past history of mankind is full of the accounts of the destruction of great nations. The root cause of the evils that caused the destruction of those nations was shirk which you are today being admonished to avoid.”
66. That is, “The Day which neither Allah Himself will avert nor has He given power to anyone else to avert it.”
67. This is a comprehensive sentence which encompasses all those harms which can afflict a disbeliever on account of his disbelief. No list of the harms could be so comprehensive as this.