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:23:68 –

Then have they not reflected over the Qur'an, or has there come to them that which had not come to their forefathers?  

God, exalted be He, says: Have they not contemplated (yaddabbarū should actually be yatadabbarū, but the tā’ has been assimilated with the dāl) the discourse, namely, the Qur’ān that is proof of the Prophet’s sincerity, or has there come upon them that which has not come upon their forefathers?
القرآن:٢٣:٦٨ –

أَفَلَمْ يَدَّبَّرُوا الْقَوْلَ أَمْ جَاءَهُمْ مَا لَمْ يَأْتِ آبَاءَهُمُ الْأَوَّلِينَ  

{أفلم يدَّبروا} أصله يتدبروا فأدغمت التاء في الدال {القول} أي القرآن الدال على صدق النبي {أم جاءهم ما لم يأت آباءهم الأولين}.