Narrated 'Aishah:

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.

أَخْبَرَنَا عِمْرَانُ بْنُ بَكَّارِ بْنِ رَاشِدٍ، قَالَ حَدَّثَنَا أَبُو الْيَمَانِ، قَالَ أَنْبَأَنَا شُعَيْبٌ، عَنِ الزُّهْرِيِّ، قَالَ أَخْبَرَنِي عُرْوَةُ بْنُ الزُّبَيْرِ، عَنْ عَائِشَةَ، أَنَّ أَبَا حُذَيْفَةَ بْنَ عُتْبَةَ بْنِ رَبِيعَةَ بْنِ عَبْدِ شَمْسٍ، - وَكَانَ مِمَّنْ شَهِدَ بَدْرًا مَعَ رَسُولِ اللَّهِ ﷺ - تَبَنَّى سَالِمًا وَأَنْكَحَهُ ابْنَةَ أَخِيهِ هِنْدَ بِنْتَ الْوَلِيدِ بْنِ عُتْبَةَ بْنِ رَبِيعَةَ بْنِ عَبْدِ شَمْسٍ وَهُوَ مَوْلًى لاِمْرَأَةٍ مِنَ الأَنْصَارِ كَمَا تَبَنَّى رَسُولُ اللَّهِ ﷺ زَيْدًا وَكَانَ مَنْ تَبَنَّى رَجُلاً فِي الْجَاهِلِيَّةِ دَعَاهُ النَّاسُ ابْنَهُ فَوَرِثَ مِنْ مِيرَاثِهِ حَتَّى أَنْزَلَ اللَّهُ عَزَّ وَجَلَّ فِي ذَلِكَ { ادْعُوهُمْ لآبَائِهِمْ هُوَ أَقْسَطُ عِنْدَ اللَّهِ فَإِنْ لَمْ تَعْلَمُوا آبَاءَهُمْ فَإِخْوَانُكُمْ فِي الدِّينِ وَمَوَالِيكُمْ } فَمَنْ لَمْ يُعْلَمْ لَهُ أَبٌ كَانَ مَوْلًى وَأَخًا فِي الدِّينِ . مُخْتَصَرٌ .