Messenger of Allah ﷺ said, any man who has a slave girl whom he educates properly, teaches good manners, manumits and marries her, will get a double reward And if any man of the people of the Scriptures believes in his own prophet and then believes in me too, he will (also) get a double reward And any slave who fulfills his duty to his master and to his Lord, will (also) get a double reward."

قَالَ رَسُولُ اللَّهِ ﷺ أَيُّمَا رَجُلٍ كَانَتْ عِنْدَهُ وَلِيدَةٌ فَعَلَّمَهَا فَأَحْسَنَ تَعْلِيمَهَا وَأَدَّبَهَا فَأَحْسَنَ تَأْدِيبَهَا ثُمَّ أَعْتَقَهَا وَتَزَوَّجَهَا فَلَهُ أَجْرَانِ وَأَيُّمَا رَجُلٍ مِنْ أَهْلِ الْكِتَابِ آمَنَ بِنَبِيِّهِ وَآمَنَ بِي فَلَهُ أَجْرَانِ وَأَيُّمَا مَمْلُوكٍ أَدَّى حَقَّ مَوَالِيهِ وَحَقَّ رَبِّهِ فَلَهُ أَجْرَانِ قَالَ الشَّعْبِيُّ خُذْهَا بِغَيْرِ شَىْءٍ قَدْ كَانَ الرَّجُلُ يَرْحَلُ فِيمَا دُونَهُ إِلَى الْمَدِينَةِ وَقَالَ أَبُو بَكْرٍ عَنْ أَبِي حَصِينٍ عَنْ أَبِي بُرْدَةَ عَنْ أَبِيهِ عَنِ النَّبِيِّ ﷺ أَعْتَقَهَا ثُمَّ أَصْدَقَهَا

'Whoever has a slave woman and teaches her good manners and educates her, then sets her free and marries her, will have two rewards. Any man from among the People of the Book who believed in his Prophet and believed in Muhammad will have two rewards. Any slave who does his duty towards Allah and towards his masters will have two rewards.” (Sahih)(one of the narrators) Salih said: “Sha'bi said: 'I have given this (Hadith) to you for little effort on your part. A rider would travel to Al-Madinah for less than this.' ” (Using translation from Ibn Mājah 1956)

قَالَ رَسُولُ اللهِ ﷺ مَنْكَانَتْ لَهُ جَارِيَةٌ فَأَدَّبَهَا فَأَحْسَنَ أَدَبَهَا وَعَلَّمَهَا فَأَحْسَنَ تَعْلِيمَهَا ثُمَّ أَعْتَقَهَا وَتَزَوَّجَهَا فَلَهُ أَجْرَانِ وَأَيُّمَا رَجُلٍ مِنْ أَهْلِ الْكِتَابِ آمَنَ بِنَبِيِّهِ وَآمَنَ بِمُحَمَّدٍ فَلَهُ أَجْرَانِ وَأَيُّمَا عَبْدٍ مَمْلُوكٍ أَدَّى حَقَّ اللهِ ﷻ عَلَيْهِ وَحَقَّ مَوَالِيهِ فَلَهُ أَجْرَانِ