It was narrated that Aishah said:'Three Sunan were established because of Barirah: She was given the choice (of whether to remain married) when she was freed, and her husband was a slave; they used to give her charity and she used to give it as a gift to the Prophet (ﷺ), and he would say: 'It is charity for her and a gift for us,' and he said, the 'Wala' is for the one who set the slave free.'"
حَدَّثَنَا عَلِيُّ بْنُ مُحَمَّدٍ، حَدَّثَنَا وَكِيعٌ، عَنْ أُسَامَةَ بْنِ زَيْدٍ، عَنِ الْقَاسِمِ بْنِ مُحَمَّدٍ، عَنْ عَائِشَةَ، قَالَتْ مَضَى فِي بَرِيرَةَ ثَلاَثُ سُنَنٍ خُيِّرَتْ حِينَ أُعْتِقَتْ وَكَانَ زَوْجُهَا مَمْلُوكًا وَكَانُوا يَتَصَدَّقُونَ عَلَيْهَا فَتُهْدِي إِلَى النَّبِيِّ ـ صلى الله عليه وسلم ـ فَيَقُولُ " هُوَ عَلَيْهَا صَدَقَةٌ وَهُوَ لَنَا هَدِيَّةٌ " . وَقَالَ " الْوَلاَءُ لِمَنْ أَعْتَقَ " .
IbnMaja
The Chapters on Divorce • Hadith 2476