Mishkat al-Masabih 14 Emancipation كتاب العتق 1

عَنْ أَبِي هُرَيْرَةَ قَالَ: قَالَ رَسُولُ اللَّهِ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ: «مَنْ أَعْتَقَ رَقَبَةً مُسْلِمَةً أَعْتَقَ اللَّهُ بِكُلِّ عُضْوٍ مِنْهُ عُضْوًا مِنَ النَّارِ حَتَّى فَرْجَهُ بِفَرْجِهِ»

Abu Huraira reported God’s Messenger as saying, “If anyone emancipates a Muslim slave, God will set free from hell a member of the body for every member of his, even his private parts for his.” (Bukhari and Muslim.)