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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
bayhaqi:12164 – Abū al-Ḥusayn b. Bishrān > Ismāʿīl b. Muḥammad al-Ṣaffār > Aḥmad b. Manṣūr > Abū al-Ḥusayn b. al-Faḍl al-Qaṭṭān > ʿAbdullāh b. Jaʿfar > Yaʿqūb b. Sufyān > ʿĪsá b. Muḥammad And ʾAbū Bishr > ʿAbd al-Razzāq > Maʿmar > Qatādah > al-Ḥasan

[Machine] Ali embraced Islam after Khadijah, when he was fifteen or sixteen years old.  

البيهقي:١٢١٦٤ – أَخْبَرَنَا أَبُو الْحُسَيْنِ بْنُ بِشْرَانَ أنبأ إِسْمَاعِيلُ بْنُ مُحَمَّدٍ الصَّفَّارُ ثنا أَحْمَدُ بْنُ مَنْصُورٍ وَأَخْبَرَنَا أَبُو الْحُسَيْنِ بْنُ الْفَضْلِ الْقَطَّانُ أنبأ عَبْدُ اللهِ بْنُ جَعْفَرٍ ثنا يَعْقُوبُ بْنُ سُفْيَانَ حَدَّثَنِي عِيسَى بْنُ مُحَمَّدٍ وَأَبُو بِشْرٍ قَالُوا ثنا عَبْدُ الرَّزَّاقِ أنبأ مَعْمَرٌ عَنْ قَتَادَةَ عَنِ الْحَسَنِ وَغَيْرِهِ وَكَانَ أَوَّلَ مَنْ آمَنَ بِهِ عَلِيُّ بْنُ أَبِي طَالِبٍ وَهُوَ ابْنُ خَمْسَ عَشْرَةَ أَوْ سِتَّ عَشْرَةَ لَفْظُ حَدِيثِهِمَا وَفِي حَدِيثِ أَحْمَدَ بْنِ مَنْصُورٍ قَالَ عَنِ الْحَسَنِ وَغَيْرِ وَاحِدٍ قَالَ أَوَّلُ

مَنْ أَسْلَمَ عَلِيٌّ بَعْدَ خَدِيجَةَ ؓ وَهُوَ ابْنُ خَمْسَ عَشْرَةَ سَنَةً أَوْ سِتَّ عَشْرَةَ سَنَةً