Caution: Translations of Quran and Ḥadīth may lead to possible misapplications and misinterpretations. This site is intended for students of sacred knowledge that are proficient in comprehending classical Arabic and have a strong foundation in Islamic sciences. Also note that religious injunctions rely on several aspects beyond what one may glean through reading individual aḥādīth.
Qurʾān Bukhārī Muslim Nasāʾī Abū Dāwūd Tirmidhī Ibn Mājah Mālik Aḥmad Dārimī Ḥākim Ibn Ḥibbān Ṭabarānī Nasāʾī's Kubrá Bayhaqī al-Luʾluʾ wa-al-Marjān Ibn Rajab's Fifty Riyāḍ al-Ṣāliḥīn Aḥmad's Zuhd Suyūṭī
quran:6:21 –

And who is more unjust than one who invents about Allah a lie or denies His verses? Indeed, the wrongdoers will not succeed.  

And who, that is, none, does greater evil than he who invents a lie against God, by ascribing to Him an associate, or denies His signs?, the Qur’ān; it is verily the case that, they the evildoers shall not prosper, on account of this.
القرآن:٦:٢١ –

وَمَنْ أَظْلَمُ مِمَّنِ افْتَرَىٰ عَلَى اللَّهِ كَذِبًا أَوْ كَذَّبَ بِآيَاتِهِ ۗ إِنَّهُ لَا يُفْلِحُ الظَّالِمُونَ  

{ومن} أي لا أحد {أظلم ممن افترى على الله كذبا} بنسبه الشريك إليه {أو كذَّب بآياته} القرآن {إنه} أي الشأن {لا يفلح الظالمون} بذلك.

See similar narrations below:

Collected by Qurʾān
quran:10:17 –

So who is more unjust than he who invents a lie about Allah or denies His signs? Indeed, the criminals will not succeed  

And who, that is, no one, does greater evil than he who invents a lie against God, by ascribing a partner to Him, or denies His signs?, ˹denies˺ the Qur’ān. Surely, it is that, the sinners, the idolaters, shall not prosper, they shall ˹never˺ find happiness.
القرآن:١٠:١٧ –

فَمَنْ أَظْلَمُ مِمَّنِ افْتَرَىٰ عَلَى اللَّهِ كَذِبًا أَوْ كَذَّبَ بِآيَاتِهِ ۚ إِنَّهُ لَا يُفْلِحُ الْمُجْرِمُونَ  

{فمن} أي لا أحد {أظلم ممن افترى على الله كذبا} بنسبة الشريك إليه {أو كذَّب بآياته} القرآن {إنه} أي الشأن {لا يفلح} يسعد {المجرمون} المشركون.
quran:29:68 –

And who is more unjust than one who invents a lie about Allah or denies the truth when it has come to him? Is there not in Hell a ˹sufficient˺ residence for the disbelievers?  

And who — in other words, there is none ˹who˺ — does greater wrong than he who invents a lie against God, by ascribing partners to Him, or denies truth, be it the Prophet or the Book, when it comes to him? Is there not in Hell a lodging, an abode, for the disbelievers?, in other words, there is such ˹an abode˺ therein and such ˹a person˺ belongs with them.
القرآن:٢٩:٦٨ –

وَمَنْ أَظْلَمُ مِمَّنِ افْتَرَىٰ عَلَى اللَّهِ كَذِبًا أَوْ كَذَّبَ بِالْحَقِّ لَمَّا جَاءَهُ ۚ أَلَيْسَ فِي جَهَنَّمَ مَثْوًى لِلْكَافِرِينَ  

{ومن} أي لا أحد {أظلم ممن افترى على الله كذبا} بأن أشرك به {أو كذب بالحق} النبي أو الكتاب {لما جاءَه أَليس في جهنم مثوىّ} مأوى {للكافرين} أي فيها ذلك وهو منهم.