The Messenger of Allah ﷺ said, "Whoever frees a believing slave, Allah the Exalted will shield from the Fire a limb of his for every limb of the freed slave."
عن رسول الله ﷺ قال: من أعتق رقبة مؤمنة وقى الله تعالى بكل عضو منها عضوا منه من النار.
Nasai narrated it in Sunan al-Kubra (4877), and Tahawi in his Mushkil (715), both from the hadith of Abu Naeem, who said, Hakam bin Abu Naam Bajali narrated to us, Fatimah bint Ali narrated to me, she said, "My father said, on the authority of the Messenger of Allah ﷺ," and he mentioned it.Its chain of transmission is hasan because of Hakam bin Abu Naam, for there is disagreement concerning him, though his hadith is hasan.