Musannaf Ibn Abi Shayba 13:3021

Abu Bakr narrated to us, he said: Waki’ narrated to us, he said: Some of the people of Medina narrated to us, from al-Maqburi, from Abu Hurayrah, who said: The Messenger of Allah (peace and blessings of Allah be upon him) said: "Whoever is appointed to the judiciary, it is as if he has been slaughtered without a knife."