Musannaf Ibn Abi Shayba 18:249

Abu Bakr narrated to us, he said: Waki' narrated to us, from Ibn Abi Layla, he said: 'Ikrimah ibn Khalid narrated to us, from a man from the family of 'Umar: The Messenger of Allah (may Allah bless him and grant him peace) decreed regarding a tooth [as blood money] five camels.