Abu Burda bin Abu Musa Ashari reported,
My son, shall I tell you a hadith my father related to me from the Messenger of Allah ﷺ? He said, "Whoever frees a slave, Allah 
will free a limb of his from the Fire for every limb of the freed slave."
Azami 6129
Hasanعن أبي بردة بن أبي موسى قال
أي بني، ألا أحدثكم حديثا حدثني أبي عن رسول الله ﷺ قال: من أعتق رقبة أعتق الله عز وجل بكل عضو منها عضوا منه من النار.
Ahmad (19623), Hakim (2/211), and Bayhaqi in Kubra (10/272) all narrated it from the hadith of Sufyan bin Uyayna, who said, Shuba the Kufan told us, saying, "We were with Abu Burda bin Abu Musa, and he said," then he mentioned it.Its chain is hasan because of Shuba, who is Ibn Dinar the Kufan. Ibn Main said, "There is no harm in him." Ibn Uyayna, Ibn Numayr, and Abu Naeem all confirmed his reliability. Yaqub bin Sufyan said, "A Kufan, there is no harm in him." He has few hadiths, and he may have only a single hadith, which is this one.