Musannaf Ibn Abi Shayba 18:932

Abu Bakr narrated to us, he said: Yazid bin Harun narrated to us, from Yahya bin Sa'id, that two men from the Bedouins disputed in Medina during the time of Umar bin Abd al-Aziz. One of them said to his companion: "I struck him, by Allah, until he defecated." He said: "Bear witness, for by Allah, he has spoken the truth." Umar bin Abd al-Aziz sent to Sa'id bin al-Musayyib asking him about a man who struck a man until he defecated: "Is there any precedent or Sunnah regarding this?" Sa'id said: "Uthman judged regarding it with one-third of the blood money (diyah)."