Sahih al-Bukhari, Hadith 3491 ⓘ

Narrated Kulaib bin Wail: I asked Zainab bint Abi Salama (i.e. daughter of the wife of the Prophet, "Tell me about the Prophet. Did he belong to the tribe of Mudar?" She replied, "Yes, he belonged to the tribe of Mudar and was from the offspring of An-Nadr bin Kinana."

حَدَّثَنَا قَيْسُ بْنُ حَفْصٍ، حَدَّثَنَا عَبْدُ الْوَاحِدِ، حَدَّثَنَا كُلَيْبُ بْنُ وَائِلٍ، قَالَ حَدَّثَتْنِي رَبِيبَةُ النَّبِيِّ، صلى الله عليه وسلم زَيْنَبُ ابْنَةُ أَبِي سَلَمَةَ قَالَ قُلْتُ لَهَا أَرَأَيْتِ النَّبِيَّ صلى الله عليه وسلم أَكَانَ مِنْ مُضَرَ قَالَتْ فَمِمَّنْ كَانَ إِلاَّ مِنْ مُضَرَ مِنْ بَنِي النَّضْرِ بْنِ كِنَانَةَ‏.‏