Ubayy ibn Ka’b reported: The Messenger of Allah, peace and blessings be upon him, said, “Two men shared their lineages in the time of Moses, upon him be peace. One man boasted to the other: I am this person, son of this person, back for nine generations. Who are you? You have no mother? The other man said: I am this person, son of this person, son of Islam. Allah revealed to Moses in regards to these two who shared their lineages: As for you tribalist, you shared lineage back for nine generations in Hellfire and you are the tenth of them. As for you, you shared lineage back for two generations in Paradise and you are the third of them.”
Source: Musnad Aḥmad 21178
Grade: Sahih (authentic) according to Al-Albani
عَنْ أُبَيِّ بْنِ كَعْبٍ قَالَ قَالَ رَسُولُ اللهِ صَلَّى اللهُ عَلَيْهِ وَسَلَّمَ انْتَسَبَ رَجُلَانِ عَلَى عَهْدِ مُوسَى عَلَيْهِ السَّلَامُ فَقَالَ أَحَدُهُمَا أَنَا فُلَانُ بْنُ فُلَانٍ حَتَّى عَدَّ تِسْعَةً فَمَنْ أَنْتَ لَا أُمَّ لَكَ قَالَ أَنَا فُلَانُ بْنُ فُلَانٍ ابْنُ الْإِسْلَامِ قَالَ فَأَوْحَى اللهُ إِلَى مُوسَى عَلَيْهِ السَّلَامُ أَنَّ هَذَيْنِ الْمُنْتَسِبَيْنِ أَمَّا أَنْتَ أَيُّهَا الْمُنْتَمِي أَوِ الْمُنْتَسِبُ إِلَى تِسْعَةٍ فِي النَّارِ فَأَنْتَ عَاشِرُهُمْ وَأَمَّا أَنْتَ يَا هَذَا الْمُنْتَسِبُ إِلَى اثْنَيْنِ فِيالْجَنَّةِ فَأَنْتَ ثَالِثُهُمَا فِي الْجَنَّةِ
21178 مسند أحمد بن حنبل
1270 المحدث الألباني خلاصة حكم المحدث إسناده صحيح رجاله ثقات في السلسلة الصحيحة