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:78:26 –

An appropriate recompense.  

as a fitting requital, one that accords with ˹the nature of˺ their deeds, for there is no sin greater than disbelief, and no chastisement greater than the Fire.
القرآن:٧٨:٢٦ –

جَزَاءً وِفَاقًا  

{جزاءً وفاقا} موافقا لعملهم فلا ذنب أعظم من الكفر ولا عذاب أعظم من النار.