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tabarani:19391Muḥammad b. ʿAbdullāh al-Ḥaḍramī > ʿUthmān b. Abū Shaybah > Abū Usāmah > Hishām b. ʿUrwah from his father

[Machine] "Khadijah passed away before the Prophet ﷺ started his mission for three years."  

الطبراني:١٩٣٩١حَدَّثَنَا مُحَمَّدُ بْنُ عَبْدِ اللهِ الْحَضْرَمِيُّ ثنا عُثْمَانُ بْنُ أَبِي شَيْبَةَ ثنا أَبُو أُسَامَةَ ثنا هِشَامُ بْنُ عُرْوَةَ عَنْ أَبِيهِ قَالَ

«تُوُفِّيَتْ خَدِيجَةُ قَبْلَ أَنْ يَخْرُجَ النَّبِيُّ ﷺ بِثَلَاثِ سِنِينَ»