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:31:3 –

As guidance and mercy for the doers of good  

it is, a guidance and a mercy (read nominative rahmatun; the popular accusative reading ˹rahmatan˺ would make it a circumstantial qualifier referring to āyāt, ‘signs’, the operator of which being the implicit demonstrative import of tilka, ‘those’) for the virtuous,
القرآن:٣١:٣ –

هُدًى وَرَحْمَةً لِلْمُحْسِنِينَ  

هو (هدى ورحمة) بالرفع (للمحسنين) وفي قراءة العامة بالنصب حالاً من الآيات العامل فيها ما في "تلك" من معنى الإشارة.

See similar narrations below:

Collected by Qurʾān
quran:27:77 –

And indeed, it is guidance and mercy for the believers.  

And truly it is a guidance, from error, and a mercy for believers, from chastisement.
القرآن:٢٧:٧٧ –

وَإِنَّهُ لَهُدًى وَرَحْمَةٌ لِلْمُؤْمِنِينَ  

{وإنه لهدى} من الضلالة {ورحمة للمؤمنين} من العذاب.