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:50:33 –

Who feared the Most Merciful unseen and came with a heart returning ˹in repentance˺.  

who fears the Compassionate One ˹while He is˺ in the Unseen, ˹the one who˺ fears Him without having seen Him, and comes with a penitent heart’, ˹a heart˺ eagerly applying itself to obedience of Him.
القرآن:٥٠:٣٣ –

مَنْ خَشِيَ الرَّحْمَٰنَ بِالْغَيْبِ وَجَاءَ بِقَلْبٍ مُنِيبٍ  

{من خشي الرحمن بالغيب} خافه ولم يره {وجاء بقلب منيب} مقبل على طاعته، ويقال للمتقين أيضا.