Messenger of Allah ﷺ said, "He who has a slave-girl and educates and treats her nicely and then manumits and marries her, will get a double reward."  

قَالَ رَسُولُ اللَّهِ ﷺ مَنْ كَانَتْ لَهُ جَارِيَةٌ فَعَالَهَا فَأَحْسَنَ إِلَيْهَا ثُمَّ أَعْتَقَهَا وَتَزَوَّجَهَا كَانَ لَهُ أَجْرَانِ  

Abu Musa reported that Messenger of Allah ﷺ said about one who emancipated a slave woman, and then married her, that for him there are two rewards.  

قَالَ رَسُولُ اللَّهِ ﷺ فِي الَّذِي يُعْتِقُ جَارِيَتَهُ ثُمَّ يَتَزَوَّجُهَا لَهُ أَجْرَانِ  

"The Messenger of Allah said: 'Whoever manumits his female slave, then marries her, he will have two rewards.'"  

قَالَ رَسُولُ اللَّهِ ﷺ مَنْ أَعْتَقَ جَارِيَتَهُ ثُمَّ تَزَوَّجَهَا فَلَهُ أَجْرَانِ  

Abu Dawud reported the Apostle of Allaah ﷺ as saying “Anyone who sets his slave girl free and then marries her, will have a double reward.” (Using translation from Abū Dāʾūd 2053)   

قَالَ رَسُولُ اللهِ ﷺ مَنْ كَانَتْ لَهُ جَارِيَةٌ فَأَعْتَقَهَا وَتَزَوَّجَهَا كَانَ لَهُ أَجْرَانِ  

"The Messenger of Allah said: 'Whoever manumits his female slave, then marries her, he will have two rewards.'" (Using translation from Nasāʾī 3345)  

قَالَ رَسُولُ اللهِ ﷺ «مَنْ أَعْتَقَ جَارِيَتَهُ ثُمَّ تَزَوَّجَهَا فَلَهُ أَجْرَانِ»