وَمَا أَرْسَلْنَا مِنْ قَبْلِكَ مِنْ رَسُولٍ وَلَا نَبِيٍّ إِلَّا إِذَا تَمَنَّى أَلْقَى الشَّيْطَانُ فِي أُمْنِيَّتِهِ فَيَنْسَخُ اللَّهُ مَا يُلْقِي الشَّيْطَانُ ثُمَّ يُحْكِمُ اللَّهُ آيَاتِهِ وَاللَّهُ عَلِيمٌ حَكِيمٌ ﴿۵۲﴾ لِيَجْعَلَ مَا يُلْقِي الشَّيْطَانُ فِتْنَةً لِلَّذِينَ فِي قُلُوبِهِمْ مَرَضٌ وَالْقَاسِيَةِ قُلُوبُهُمْ وَإِنَّ الظَّالِمِينَ لَفِي شِقَاقٍ بَعِيدٍ ﴿۵۳﴾

﴾52﴿ Wa maaa arsalnaa min qablika mir Rasoolinnw wa laa Nabiyyin illaaa izaaa tamannaaa alqash Shaitaanu feee umniy yatihee fa yansakhul laahu maa yulqish Shaitaanu summa yuhkimul laahu aayaatih; wallaahu 'Aleemun Hakeem
﴾53﴿ Liyaj'ala maa yulqish Shaitaanu fitnatal lillazeena fee quloobihim maradunw walqaasiyati quloobuhum; wa innaz zaalimeena lafee shiqaaqim ba'eed

﴾52﴿ And We did not send before you any messenger or prophet except that when he recited [the message], Satan threw [into it some falsehood]. But Allah abolishes what Satan throws in; then Allah establishes His verses firmly. And Allah is All-Knowing, All-Wise
﴾53﴿ (This is so) that He may make what Satan throws a trial for those in whose hearts is a disease and for those whose hearts are hardened. And indeed, the wrongdoers are in extreme opposition

[52] After mentioning the two groups (believers and disbelievers), this verse explains their separate causes:
The cause of disbelief is the whispers and doubts cast by human and jinn devils, while the cause of faith is that Allah removes those whispers and doubts from the hearts of the believers.
The phrase “مِنْ رَسُولٍ وَلَا نَبِيٍّ” highlights the distinction between a Rasūl and a Nabī, and scholars mention several differences:
1. First view (relational): A Rasūl is one who delivers a message from Allah, while a Nabī is one who informs people of divine truths. 2. Second view (based on scripture): A Rasūl is someone who receives a divine book or written revelation, while a Nabī may not have a new scripture but still receives divine guidance. 3. Third view (scope): A Rasūl can refer to angels as well, as they deliver Allah’s messages, while Nabī is specific to humans.
The phrase “إِذَا تَمَنَّى” here means when he recites or proclaims revelation—this usage is found in classical Arabic poetry as well.
“أَلْقَى الشَّيْطَانُ فِي أُمْنِيَّتِهِ” means that when the Prophet recites the revelation, the devils among jinn and humans try to cast doubts and spread accusations in the hearts of others—like saying: "He is mad," "a sorcerer," "a soothsayer," "a liar," etc.
But “فَيَنْسَخُ اللَّهُ مَا يُلْقِي الشَّيْطَانُ” means that Allah removes those doubts through revelation, canceling and erasing what the Shayṭān tries to insert.
Then, “ثُمَّ يُحْكِمُ اللَّهُ آيَاتِهِ” means that Allah strengthens and perfects His verses, supporting the Prophet's message with clear proofs and responses to the doubts, making his call to truth firm and unshakable.
[53] This part of the verse is connected to “أَلْقَى الشَّيْطَانُ”—it explains the wisdom behind Allah allowing Shayṭān to cast doubts.
It means that Allah has granted this ability to Shayṭān as a form of test and trial for two types of people: – Those who have doubt in their hearts (i.e., the hypocrites), – And those with hardened hearts (i.e., the disbelievers).
As a result, they become more fixed in their doubt and disbelief, and are eventually trapped in severe enmity toward the truth.
Thus, the casting of doubts serves to expose the insincere and confirm their distance from guidance.