The Messenger of Allah ﷺ said, "A child cannot repay his father, unless he finds him as a slave and buys him and sets him free."
حدثنا أبو كامل حدثنا زهير عن سهيل عن أبيه
قال رسول الله ﷺ لا يجزي ولد والده إلا أن يجده مملوكا فيشتريه فيعتقه
Its isnad is sahih, and it is a repeat of 7143.