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:36:6 –

That you may warn a people whose forefathers were not warned, so they are unaware.  

that you may warn, therewith, a people (qawman, connected to tanzīla, ‘a revelation’) whose fathers were not warned, in the period of the interval (al-fatra), so they, this people, are oblivious, to faith and right guidance.
القرآن:٣٦:٦ –

لِتُنْذِرَ قَوْمًا مَا أُنْذِرَ آبَاؤُهُمْ فَهُمْ غَافِلُونَ  

{لتنذرَ} به {قوما} متعلق بتنزيل {ما أنذر آباؤهم} أي لم ينذروا في زمن الفترة {فهم} أي القوم {غافلون} عن الإيمان والرشد.