A man from the Ansar freed a slave of his on condition that he would become free upon the master's death, and he had no other property besides him. Word of this reached the Prophet ﷺ, who said, "Who will buy him from me?" Naeem bin Abdullah purchased him for eight hundred dirhams, and the Prophet ﷺ handed the money over to him.Amr said, I heard Jabir bin Abdullah say, "He was a Coptic slave who died the previous year."
أن رجلا من الأنصار أعتق غلاما له عن دبر لم يكن له مال غيره، فبلغ ذلك النبي ﷺ، فقال: من يشتريه مني؟ فاشتراه نعيم بن عبد الله بثمانمائة درهم، فدفعها إليه. قال عمرو: سمعت جابر بن عبد الله يقول: عبدا قبطيا مات عام أول.
Bukhari narrated it in the Book of Emancipation (2534) via Shubah, and Muslim narrated it in the Book of Oaths and Vows (997:58) via Hammad bin Zayd, both of them from Amr bin Dinar, from Jabir bin Abdullah, who related it. The wording given is that of Muslim.His saying, "regarding a slave freed after his death," means he tied the slave's emancipation to his own death, since death comes after life.