Sahih Muslim , Book 8, Hadith 3327 (USC-MSA) ⓘ
Abu Musa reported that Allah's Messenger said about one who emancipated a slave woman, and then married her, that for him there are two rewards.
وَحَدَّثَنَا يَحْيَى بْنُ يَحْيَى، أَخْبَرَنَا خَالِدُ بْنُ عَبْدِ اللَّهِ، عَنْ مُطَرِّفٍ، عَنْ عَامِرٍ، عَنْ أَبِي بُرْدَةَ، عَنْ أَبِي مُوسَى، قَالَ قَالَ رَسُولُ اللَّهِ صلى الله عليه وسلم فِي الَّذِي يُعْتِقُ جَارِيَتَهُ ثُمَّ يَتَزَوَّجُهَا " لَهُ أَجْرَانِ " .
also referenced under: Book 16, Hadith 101 (In-Book) & Hadith 154 (Reference)