سنن ابن ماجه

It was narrated from Abu Umamah bin Sahl bin Hunaif that a man shot an arrow at another man and killed him, and he had no heir except a maternal uncle. Abu ‘Ubaidah bin Jarrah wrote to ‘Umar about that, and ‘Umar wrote back to him saying that the Prophet (ﷺ) said: “Allah and His Messenger are the guardians of the one who has no guardian, and the maternal uncle is the heir of one who has no other heir.”