It was narrated from 'Aishah that Abu Hudhaifah bin 'Utbah bin Rabi'ah bin 'Abd Shams --who was one of those who had been present at Badr with the Messenger of Allah-- adopted Salim and married him to his brother's daughter, Hind bint Al-Walid bin 'Utbah bin Rabi'ah bin 'Abd Shams, and he was a freed slave of an Ansari woman --as the Messenger of Allah had adopted Zaid. During the Jahiliyyah, if a man adopted someone, the people would call him his son, and he would inherit from his legacy, until Allah, the Mighty and Sublime, revealed about that: 'Call them by (the names of) their fathers, that is more just with Allah. But if you know not their fathers' (names, call them) your brothers in Faith and Mawalikum (your freed slaves)." Then if a person's father's name was not known, he would be their freed slave and brother in faith. (Using translation from Nasāʾī 3223)

أَنَّ أَبَا حُذَيْفَةَ بْنَ عُتْبَةَ بْنِ رَبِيعَةَ بْنِ عَبْدِ شَمْسٍ وَكَانَ مِمَّنْ شَهِدَ بَدْرًا مَعَ رَسُولِ اللهِ ﷺ تَبَنَّى سَالِمًا وَزَوَّجَهُ ابْنَةَ أَخِيهِ هِنْدَ بِنْتَ الْوَلِيدِ بْنِ عُتْبَةَ وَهُوَ مَوْلًى لِامْرَأَةٍ مِنَ الْأَنْصَارِ كَمَا تَبَنَّى النَّبِيُّ ﷺ زَيْدًا وَكَانَ مَنْ تَبَنَّى رَجُلًا فِي الْجَاهِلِيَّةِ دَعَاهُ النَّاسُ ابْنَهُ وَوَرِثَ مِنْ مِيرَاثِهِ حَتَّى أَنْزَلَ اللهُ ﷻ فِي ذَلِكَ {ادْعُوهُمْ لِآبَائِهِمْ هُوَ أَقْسَطُ عِنْدَ اللهِ فَإِنْ لَمْ تَعْلَمُوا آبَاءَهُمْ فَإِخْوَانُكُمْ فِي الدِّينِ وَمَوَالِيكُمْ} [الأحزاب 5] فَرُدُّوا إِلَى آبَائِهِمْ فَمَنْ لَمْ يُعْلَمْ لَهُ أَبٌ كَانَ مَوْلًى وَأَخًا