Sahih Muslim , Book 9, Hadith 3604 (USC-MSA) ⓘ
Abu Huraira (Allah be pleased with him) reported: I heard Allah's Messenger as saying: He who emancipates a believing slave. Allah will set free from Fire his every limb for every limb of his (slave's), even his private parts for his.
وَحَدَّثَنَا قُتَيْبَةُ بْنُ سَعِيدٍ، حَدَّثَنَا لَيْثٌ، عَنِ ابْنِ الْهَادِ، عَنْ عُمَرَ بْنِ عَلِيِّ بْنِ حُسَيْنٍ، عَنْ سَعِيدِ ابْنِ مَرْجَانَةَ، عَنْ أَبِي هُرَيْرَةَ، قَالَ سَمِعْتُ رَسُولَ اللَّهِ صلى الله عليه وسلم يَقُولُ " مَنْ أَعْتَقَ رَقَبَةً مُؤْمِنَةً أَعْتَقَ اللَّهُ بِكُلِّ عُضْوٍ مِنْهُ عُضْوًا مِنَ النَّارِ حَتَّى يُعْتِقَ فَرْجَهُ بِفَرْجِهِ" .
also referenced under: Book 20, Hadith 27 (In-Book) & Hadith 1509 (Reference)