إِنَّ الَّذِينَ يُلْحِدُونَ فِي آيَاتِنَا لَا يَخْفَوْنَ عَلَيْنَا أَفَمَنْ يُلْقَى فِي النَّارِ خَيْرٌ أَمْ مَنْ يَأْتِي آمِنًا يَوْمَ الْقِيَامَةِ اعْمَلُوا مَا شِئْتُمْ إِنَّهُ بِمَا تَعْمَلُونَ بَصِيرٌ ﴿۴۰﴾ إِنَّ الَّذِينَ كَفَرُوا بِالذِّكْرِ لَمَّا جَاءَهُمْ وَإِنَّهُ لَكِتَابٌ عَزِيزٌ ﴿۴۱﴾ لَا يَأْتِيهِ الْبَاطِلُ مِنْ بَيْنِ يَدَيْهِ وَلَا مِنْ خَلْفِهِ تَنْزِيلٌ مِنْ حَكِيمٍ حَمِيدٍ ﴿۴۲﴾ مَا يُقَالُ لَكَ إِلَّا مَا قَدْ قِيلَ لِلرُّسُلِ مِنْ قَبْلِكَ إِنَّ رَبَّكَ لَذُو مَغْفِرَةٍ وَذُو عِقَابٍ أَلِيمٍ ﴿۴۳﴾

﴾40﴿ Innal lazeena yulhidoona feee Aayaatina laa yakhfawna 'alainaa' afamai yulqaa fin Naari khayrun am mai yaateee aaminai Yawmal Qiyaamah; i'maloo ma shi'tum innahoo bimaa ta'maloona Baseer
﴾41﴿ Innal Lazeena kafaroo biz Zikri lammaa jaa'ahum wa innahoo la Kitaabun 'Azeez
﴾43﴿ Maa yuqaalu laka illaa maa qad qeela lir Rusuli min qablik; inna Rabbaka lazoo maghfiratinw wa zoo 'iqaabin aleem
﴾44﴿ Wa law ja'alnaahu Qur-aanan A'jamiyyal laqaaloo law laa fussilat Aayaatuhoo 'a A'jamiyyunw wa 'Arabiyy; qul huwa lillazeena aamanoo hudanw wa shifaaa'unw wallazeena la yu'minoona feee aazaanihim waqrunw wa huwa 'alaihim 'amaa; ulaaa'ika yunaadawna mim maakaanim ba'eed

﴾40﴿ Indeed, those who deviate concerning Our signs are not hidden from Us. So, is the one who is cast into the Fire better, or the one who comes secure on the Day of Resurrection? Do as you will; indeed, Allah is All-Seeing of what you do
﴾41﴿ Indeed, those who disbelieve in the Quran when it comes to them (will be doomed). And indeed, it is a Book of great honor
﴾42﴿ Falsehood cannot approach it from before it or from behind it; it has been sent down from the One who is All-Wise, Most Praiseworthy
﴾43﴿ Nothing is said to you except what was said to the messengers before you. Indeed, your Lord is the Possessor of Forgiveness and the Possessor of a painful punishment

[40] This relates to the verse "Do not listen to this Qur'an" — meaning, they practice deviation (ilhād) in the verses through such methods as preventing people from listening to it, making false distortions and interpretations, and opposing it.
So, they are warned and threatened in three ways as a rebuke.
[41,42] This is also a warning to those who deviate from the Qur'an, along with a statement of its truthfulness through four attributes.
‘Azīz — this word has many meanings, and all are intended: it is honored in the sight of Allah the Exalted, dominant over every other book, without equal or comparison, and beloved — meaning no one is able to challenge it.
"Falsehood cannot come to it" (lā ya’tīhi al-bāṭil) — falsehood here may refer to alteration and distortion, or denial, or Satan.
"From before it nor from behind it" — both sides are mentioned, and the meaning is from all directions, i.e., no kind of falsehood in any of these three meanings can ever approach it from any cause.
Or it may mean past events and future prophecies, and falsehood here refers to denial.
Or it may refer to previously revealed books and future revelations — meaning, there is no denial of this Qur'an in previous scriptures, nor can any new book come after it to abrogate it.
This is proof that this is the final Book revealed to the final Prophet.
[43] This is a consolation to the Messenger of Allah (May Allah bless him and give him peace) after the mention of those who deviate from the Qur'an.
There are two interpretations of the verse:
First: "What was said to the messengers" refers to the insults and accusations made against them, such as being called a sorcerer, liar, madman, misguided, and so on.
Second: It refers to the revelation of Tawhid — that the same message of monotheism was sent to the previous messengers as well.