اَلْیَوْمَ This Day نَخْتِمُ We will seal عَلٰۤی [on] اَفْوَاهِهِمْ their mouths وَ تُكَلِّمُنَاۤ and will speak to Us اَیْدِیْهِمْ their hands وَ تَشْهَدُ and will bear witness اَرْجُلُهُمْ their feet بِمَا about what كَانُوْا they used (to) یَكْسِبُوْنَ earn وَ لَوْ And if نَشَآءُ We willed لَطَمَسْنَا We (would have) surely obliterated عَلٰۤی [over] اَعْیُنِهِمْ their eyes فَاسْتَبَقُوا then they (would) race الصِّرَاطَ (to find) the path فَاَنّٰی then how یُبْصِرُوْنَ (could) they see وَ لَوْ And if نَشَآءُ We willed لَمَسَخْنٰهُمْ surely We (would have) transformed them عَلٰی in مَكَانَتِهِمْ their places فَمَا then not اسْتَطَاعُوْا they would have been able مُضِیًّا to proceed وَّ لَا and not یَرْجِعُوْنَ۠ return وَ مَنْ And (he) whom نُّعَمِّرْهُ We grant him long life نُنَكِّسْهُ We reverse him فِی in الْخَلْقِ ؕ the creation اَفَلَا Then will not یَعْقِلُوْنَ they use intellect وَ مَا And not عَلَّمْنٰهُ We taught him الشِّعْرَ [the] poetry وَ مَا and not یَنْۢبَغِیْ it is befitting لَهٗ ؕ for him اِنْ Not هُوَ it اِلَّا (is) except ذِكْرٌ a Reminder وَّ قُرْاٰنٌ and a Quran مُّبِیْنٌۙ clear
(36:65) Today We shall put a seal on their mouths, and their hands will speak to Us and their feet shall bear witness to what they had been doing.55
(36:66) If We so willed, We would have put out their eyes, then they would rush to see the Way, but how would they be able to see?
(36:67) If We so willed, We would have transformed them where they were so that they would not go forward or backward.56
(36:68) Whomsoever We grant a long life, We reverse him in his constitution.57 Do they still not understand?
(36:69) We did not teach him (to wit, the Messenger) poetry and it does not behove him.58 This is none but an Admonition, and a Clear Book
55. This command will be issued as regards those supercilious culprits who simply refuse to own their guilt, deny the testimony of the witnesses, and contest the veracity of their scroll of deeds. It is at this point that God will call a halt to their protestations, and will ask them to witness the tale of their misdeeds as narrated by their own limbs. Mention is made here only of the testimony given by the hands and feet of these culprits.
At other places, however, it is stated that their eyes, ears, tongues and skins will bear testimony to their misdeeds. The following verses are illustrative: “They should not disregard the Day when their own tongues, their hands and their feet will testify against their misdeeds” (al-Nar 24:24), and “When they reach there, their ears, their eyes and their skin will testify to what they did” (Ha’ Mim al-Sajdah 41:20).
One is, however, faced with a difficulty in this regard. For, on the one hand, God declares that He will seal their mouths while at another place it is asserted that their tongues will testify against them. So, how does one reconcile these two statements? In our opinion, the sealing of their mouths means depriving them of the faculty of speech. In other words, it will no longer be possible for them to speak as they like. As for the testimony by the tongues, it means that they themselves will relate their misdeeds. Their tongues will elaborate upon how they were put to misuse by these wrong-doers in uttering blasphemy and lies and in fomenting mischief.
56. After depicting a scene of the Hereafter, the unbelievers are reminded of how they dismissed the Afterlife as something quite remote from reality. Yet they should observe with open eyes that in fact in this life too they are quite helpless beings under the control of the All-Mighty God. True, they are able to see everything around them with their eyes, but a simple command from God can make them instantly blind. Likewise, their legs which enable them to move about freely can be paralyzed by God’s command, thus rendering them incapable of even walking a step.
As long as people enjoy the physical faculties granted to them by God, they remain deluded by an overly inflated egotism. As soon as they lose ‘any of these faculties, they realize the true extent of their helplessness.
57. What is emphasized here is that in old age one is reverted to the state of one’s infancy. The elderly suffers from the same weaknesses, infirmities and dependencies that marked their infant lives. Others help them to rise and put them to bed and feed them. They even lose control over themselves in such ordinary matters as answering the call of nature.
Furthermore, they engage in foolish prattle causing people to burst into.
laughter. In short, in old age they revert to the same stage of weakness through which they had passed in their infancy.
58. This constitutes the Qur’anic rejoinder to the unbelievers’ dismissal of the Prophet's statements about monotheism, the Hereafter, Life-after-Death, Paradise and Hell, as sheer poetry. For them, these statements were as worthless as flights of fancy which one notes in poetry.
(For further details see Towards Understanding the Qur'an, Surah al-Shu‘ara’ 26: nn. 142-145, Vol. VII, pp. 126-129.)