Abu Hurairah (RAA) narrated that The Messenger of Allah (ﷺ) said:
"Any Muslim, who emancipates another Muslim man, Allah will set free from Hell Fire an organ of his body, for every organ of the other's (i.e. from the body of the emancipated person )." Agreed upon.
English reference: Book 15, Hadith 1462
Arabic reference: Book 15, Hadith 1418