From Sahih Bukhari (Hadith 2517):
Narrated Abu Huraira:The Prophet (ﷺ) said, "Whoever frees a Muslim slave, Allah will save all the parts of his body from the (Hell) Fire as he has freed the body-parts of the slave." Sa`id bin Marjana said that he narrated that Hadith to `Ali bin Al-Husain and he freed his slave for whom `Abdullah bin Ja`far had offered him ten thousand Dirhams or one-thousand Dinars
Reference: Bukhari 2517