Musannaf Ibn Abi Shayba 18:1081

Abu Bakr narrated to us, he said: Zayd ibn al-Hubab narrated to us, from Abdullah ibn Mu’ammil, he said: Umar ibn Abd al-Rahman al-Sahmi narrated to me, from Ata ibn Abi Rabah, from Abu Umayyah ibn al-Akhnas, he said: I was sitting with Umar ibn al-Khattab when a man from Banu Ghifar came and said: "My father has a head wound (shajj)." He (Umar) said: "The people of the villages do not pay the blood money (diya) for this among themselves."