Sahih Muslim
The Book of Divorce (Kitab Al-Talaq)
Book Number: 009 / Hadith Number: 3603
Abu Huraira (Allah be pleased with him) reported Allah's Messenger (may peace benpon him) as saying: He who emancipates a slave, Allah will set free from Hell every limb (of his body) for every limb of his (slave's) body, even his private parts.