Sunan Abi Dawud, Hadith 1686 ⓘ
Maimunah, wife of the Probhet said : I had a slave girl and I set her free. When the Prophet entered upon me, I informed him (of this). He said : May Allah give reward for it; if you had given her to your maternal uncles, it would have increased your reward
حَدَّثَنَا هَنَّادُ بْنُ السَّرِيِّ، عَنْ عَبْدَةَ، عَنْ مُحَمَّدِ بْنِ إِسْحَاقَ، عَنْ بُكَيْرِ بْنِ عَبْدِ اللَّهِ بْنِ الأَشَجِّ، عَنْ سُلَيْمَانَ بْنِ يَسَارٍ، عَنْ مَيْمُونَةَ، زَوْجِ النَّبِيِّ صلى الله عليه وسلم قَالَتْ كَانَتْ لِي جَارِيَةٌ فَأَعْتَقْتُهَا فَدَخَلَ عَلَىَّ النَّبِيُّ صلى الله عليه وسلم فَأَخْبَرْتُهُ فَقَالَ " آجَرَكِ اللَّهُ أَمَا إِنَّكِ لَوْ كُنْتِ أَعْطَيْتِهَا أَخْوَالَكِ كَانَ أَعْظَمَ لأَجْرِكِ " .
also referenced under: Hadith 1690 (DarusSalam)