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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
muslim:135d – Muḥammad b. Ḥātim > Kathīr b. Hishām > Jaʿfar b. Burqān > Yazīd b. al-Aṣam > Abū Hurayrah

I heard Abu Huraira saying that the Messenger of Allah ﷺ observed: people will certainly ask you about everything till they will propound: Allah created every thing, but who created Allah?  

مسلم:١٣٥d – حَدَّثَنِي مُحَمَّدُ بْنُ حَاتِمٍ حَدَّثَنَا كَثِيرُ بْنُ هِشَامٍ حَدَّثَنَا جَعْفَرُ بْنُ بُرْقَانَ حَدَّثَنَا يَزِيدُ بْنُ الأَصَمِّ قَالَ سَمِعْتُ أَبَا هُرَيْرَةَ يَقُولُ

قَالَ رَسُولُ اللَّهِ ﷺ لَيَسْأَلَنَّكُمُ النَّاسُ عَنْ كُلِّ شَىْءٍ حَتَّى يَقُولُوا اللَّهُ خَلَقَ كُلَّ شَىْءٍ فَمَنْ خَلَقَهُ  

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Collected by Bukhārī
bukhari:7296 – al-Ḥasan b. Ṣabbāḥ > Shabābah > And Rqāʾ > ʿAbdullāh b. ʿAbd al-Raḥman > Anas b. Mālik

Messenger of Allah ﷺ said, "People will not stop asking questions till they say, 'This is Allah, the Creator of everything, then who created Allah?' "  

البخاري:٧٢٩٦ – حَدَّثَنَا الْحَسَنُ بْنُ صَبَّاحٍ حَدَّثَنَا شَبَابَةُ حَدَّثَنَا وَرْقَاءُ عَنْ عَبْدِ اللَّهِ بْنِ عَبْدِ الرَّحْمَنِ سَمِعْتُ أَنَسَ بْنَ مَالِكٍ يَقُولُ

قَالَ رَسُولُ اللَّهِ ﷺ لَنْ يَبْرَحَ النَّاسُ يَتَسَاءَلُونَ حَتَّى يَقُولُوا هَذَا اللَّهُ خَالِقُ كُلِّ شَىْءٍ فَمَنْ خَلَقَ اللَّهَ