The Messenger of Allah ﷺ said, "Whoever frees a slave will have, for the freeing of each limb of the slave, a limb of his own redeemed from the Fire," until he mentioned the private parts.Then Ali bin Husayn called for a slave of his and freed him.
حدثنا وكيع قال حدثني عبد الله بن سعيد يعني ابن أبي هند عن إسماعيل بن أبي حكيم عن سعيد ابن مرجانة أنه حدث علي بن حسين
أن رسول الله ﷺ قال من أعتق رقبة كان له بعتق كل عضو منه عضو من النار حتى ذكر الفرج قال فدعا علي بن حسين غلاما له فأعتقه
Its isnad is sahih, Saeed is Ibn Marjana, a trustworthy narrator, and not Ibn Yasar, and Abdullah bin Saeed makes occasional mistakes but has been corroborated. The hadith is found in Bukhari and Muslim as mentioned previously in 9506.