Musannaf Ibn Abi Shayba 18:862

Abu Bakr narrated to us, he said: Abd al-Salam ibn Harb narrated to us, from Khusayf, from Mujahid, that a man came to Umar and said: "A man accepted Islam at my hands, then he died and left behind a thousand dirhams. I felt uneasy about them, so I have brought them to you." He (Umar) said: "Do you see, if he had committed a crime, upon whom would it have been?" He said: "Upon me." He said: "Then his inheritance is for you."