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:76:10 –

Indeed, We fear from our Lord a Day austere and distressful."  

Indeed we fear from our Lord a day of frowning, one in which faces scowl, in other words, a horrid day to observe on account of its severity, calamitous’, severe in that respect.
القرآن:٧٦:١٠ –

إِنَّا نَخَافُ مِنْ رَبِّنَا يَوْمًا عَبُوسًا قَمْطَرِيرًا  

{إنا نخاف من ربنا يوما عبوْسا} تكلح الوجوه فيه أي كريه المنظر لشدته {قمطريرا} شديدا في ذلك.