Musannaf Ibn Abi Shayba 18:884

Abu Bakr narrated to us, he said: Ibn al-Mubarak narrated to us, from Ma’mar, from ‘Amr ibn ‘Abd Allah, from ‘Ikrimah, from ‘Umar ibn al-Khattab: He decreed the blood money (diyah) upon the people of the villages to be twelve thousand. And he said: "Indeed, the times change, and I fear for you the rulers after me. So there is no increase upon the people of the villages in the aggravation of the blood money, nor in the sacred month, nor in the sacred territory. The blood money of the people of the villages has no aggravation in it, and there is no increase in it."