Musannaf Ibn Abi Shaybah 29880 — A man who comes under safe conduct

Yusuf bin Ya'qub said: A man from among the polytheists killed a man from among the Muslims, then he entered under a guarantee of safety, and the brother of that Muslim killed him. So Umar bin Abd al-Aziz ruled against him that he must pay blood money (diyah), laid the burden of it on his own wealth, confined him in prison, and sent the blood money to the slain man's heirs among the people of war.