Musnad Ahmad 2:264

Abu al-Mundhir Asad ibn ‘Amr narrated to us—I think it is from Hajjaj, from ‘Amr ibn Shu‘ayb, from his father, from his grandfather, who said: A man killed his son intentionally, so he was brought before ‘Umar ibn al-Khattab. He imposed upon him one hundred camels: thirty hiqqah, thirty jadha‘ah, and forty thaniyyah. He said: "The killer does not inherit. And were it not that I heard the Messenger of Allah, peace and blessings of Allah be upon him, say: 'A father shall not be killed for his child,' I would have killed you."