Musannaf Ibn Abi Shaybah

Hazrat Malik bin Anas (may Allah be pleased with him) narrates that Hazrat Hani bin Hizam said: A man found another man with his wife and killed him. This matter was written to Hazrat Umar, so Hazrat Umar wrote two letters regarding this: one public letter that the man should be killed, and one secret letter that blood money should be taken from him.