Sahih Muslim Book 009, Hadith Number 3605.
Chapter: Excellence of emancipating a slave.
Abu Huraira (Allah be pleased with him) reported Allah's Messenger (may peace be upon him) as saying: A Muslim who emancipates a Muslim (slave). Allah will save from Fire every limb of his for every limb (of the slave). Sa'id b. Marjana said: When I heard this hadith from Abu Huraira (Allah be pleased with him), I went away and made a mention of it to 'Ali b. Husain and he at once emancipated the slave for which Ibn ja'far was prepared to pay ten thousand dirhams or one thousand dinars.