Musnad Ahmad 31:844

Aswad ibn Amir narrated to us, Abu Isra’il Isma’il al-Mala’i narrated to us, from Atiyyah, from Abu Sa’id, who said: "A slain person was found between two villages—or a dead person—so the Messenger of Allah, peace and blessings of Allah be upon him, commanded that the distance between the two villages be measured to see to which of them he was closer. He was found to be closer to one of them by a span—he said: 'It is as if I am looking at the span of the Messenger of Allah, peace and blessings of Allah be upon him'—so he assigned him to the one he was closer to."