Chapter 19: Shares of Inheritance (Kitab Al-Fara'id)
Al-Hasan reported that Umar asked: Which of your knows what share the Messenger of Allah (ﷺ) had given to the grandfather from the estate? Ma' qil ibn Yasar said: The Messenger of Allah (ﷺ) gave him a sixth. He asked: Along with whom? He replied: I do not know. He said: You do not know; what is the use then?
Sunan Abi Dawud 2897