Surah Al-Mutaffifin (Defrauding — المطففين) (Ayah 13)

كِتَابٌ مَّرْ‌قُومٌ (A register inscribed!...Al-Mutaffifin 83:9 ^⧉ ) The word marqum (translated above as 'inscribed' ) signifies here makhtum meaning 'sealed'. Imam Baghawi and Ibn Kathir say that this statement is not the interpretation of sijjin, but rather the explication of a phrase before that, namely:

كِتَابَ الْفُجَّارِ‌

'Indeed the record of deeds of the sinners is in sijjin. Al-Mutaffifin 83:7 ^⧉ '

It is a book inscribed and sealed. No one can add anything to it, nor can anyone remove anything from it, nor is any alteration possible in it. The place where it will be kept for safe-custody is called sijjin, and it is the place where the souls of the wicked unbelievers are gathered.

كَلَّا سکتہ إِنَّهُمْ عَن رَّ‌بِّهِمْ يَوْمَئِذٍ لَّمَحْجُوبُونَ (No! But that which they used to commit has covered their hearts with rust...Al-Mutaffifin 83:14 ^⧉). The word rana is derived from rain and it means 'rust' or 'dust' or 'filth'. In other words, the rust of committing many sins has covered up their hearts. Just as rust consumes the iron, and turns it into dust, in the same way, the rust of while he was on the upper horizon....An-Najm 53:7 ^⧉)