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Surah 68. Al-Qalam
Ayah 42 - 43
42 يَوْمَ يُكْشَفُ عَن سَاقٍ وَيُدْعَوْنَ إِلَى ٱلسُّجُودِ فَلَا يَسْتَطِيعُونَ
43 خَـٰشِعَةً أَبْصَـٰرُهُمْ تَرْهَقُهُمْ ذِلَّةٌ ۖ وَقَدْ كَانُوا۟ يُدْعَوْنَ إِلَى ٱلسُّجُودِ وَهُمْ سَـٰلِمُونَ
[42-43] The Day the affliction befalls24 and the people are called upon to prostrate themselves, they will not be able to prostrate themselves. Their eyes downcast, abjectness will be covering them. Yet when they were safe and sound they used to be called upon to prostrate themselves (but they refused to do so).25
24Literally: "The Day the shin shall be uncovered". A section of the Companions and their successors says that these words have been used idiomatically, for according to Arabic idiom, kashf-i saq implies befalling of an affliction. Hadrat `Abdullah bin 'Abbas also has given this same meaning of this and has supported it by evidence from Arabic poetry. According to another saying that has been cited from Ibn 'Abbas and Rabi' bin Anas, kashf-i saq implies uncovering the facts and truths. In view of this interpretation, the meaning would be: "The Day when all truths shall be bared and the people's deeds shall become open and manifest. "
25It means: On the Resurrection Day it will be openly and publicly demonstrated as to who in the world had actually worshiped Allah and who was disinclined to do so. For this purpose the people will be called upon to prostrate themselves before Allah. Then, those who had been sincerely worshiping Allah in the world, would prostrate themselves, and those who had declined to bow before Him in the world, would be unable to do so. It will become impossible for them to put up a false show of being worshipers. Therefore, they will remain standing, degraded and downcast with shame.