Allah the Exalted states that the criminals are misguided away from the truth and engulfed in confusion, because of the doubts and uncertainty they are in. This description befits every disbeliever and innovator of all types and forms of sects. Allah the Exalted said,
يَوْمَ يُسْحَبُونَ فِى النَّارِ عَلَى وُجُوهِهِمْ
(The Day they will be dragged on their faces into the Fire), meaning, just as they were consumed in doubt, suspicion and hesitation, they ended up in the Fire. And just as they were misguided, they will end up being dragged on their faces, unaware of where they will be taken. They will be admonished and criticized,
The word زُبُر zubur (in verse 43) is the plural of zabur, which stands for any written book. It specifically refers to the Scripture that was revealed to Prophet Dawud (علیہ السلام) .
أَدْهَىٰ وَأَمَرُّ (...more calamitous and more bitter...54:46). The word adha means more or most calamitous. The word amarr is derived from murr which originally means 'bitter'. By extension anything 'difficult' or 'painful' is also referred to as amarr and murr. In the phrase فِي ضَلَالٍ وَسُعُرٍ fi dalalin wa su'ur, dalal, as is known, means 'error' or 'deviation' and the word su'ur in the present context means the 'Hell-Fire1.' In the phrase ashya'akum, (verse 51) ashya` is the plural of shi'ah, and it means a 'follower', that is, those who follow their pattern of life.
(1). This is according to one interpretation. The other meaning of the word is 'madness' and the translation in the text is based on this meaning. (Muhammad Taqi Usmani
In the phrase مَقْعَدِ صِدْقٍ maq` adi-sidqin, the word maq'ad means 'seat' and the word sidq means 'truth' and implies the 'seat of truth' where there will be no idle and obscene talks.
Tazkirul Quran
Maulana Wahiduddin KhanOn ayahs 48–54
For those who refused to accept the Prophet Muhammad, there was a lesson in the fatal incidents which befell those who rejected the earlier prophets. But they did not learn from this. This has been true of all the peoples. In spite of clear signs, every community has considered itself safe from God’s ire and therefore exempt from religious obligations. Every community has indulged in the same arrogant behaviour as the previous communities, as a result of which they have had to suffer God’s retribution.
Uthmani text of the Madinah mushaf (King Fahd Complex). Translation: Saheeh International. Tafsir via Quran.com.