Musannaf Ibn Abi Shaybah

It is narrated from Muhammad, may Allah have mercy on him, that a man made his slave a mukatab (contracted for freedom), and stipulated for himself the right of wala’, inheritance, and the house. When the slave paid the price of his freedom, he became free. Then he passed away, and after his death, his heirs disputed over the inheritance. Hazrat Shurayh, may Allah have mercy on him, invalidated this. His master said, “What benefit did I get from the condition I set for a year?” Hazrat Shurayh replied: “Allah’s condition has existed for fifty years before you, and it has more right.”