Musnad Ahmad 2:266

Ya'qub narrated to us, my father narrated to us, from Ibn Ishaq, Abdullah ibn Abi Najih and 'Amr ibn Shu'ayb narrated to me, both of them from Mujahid ibn Jabr, and he mentioned the hadith, and he said: 'Umar took from the camels thirty *hiqqah* (three-year-old camels), thirty *jadha'ah* (four-year-old camels), and forty *thaniyyah* (five-year-old camels) up to *bazil* (six-year-old camels) of their year, all of them pregnant. He said: Then he called the brother of the murdered man and gave them to him, excluding his father. And he said: I heard the Messenger of Allah, peace and blessings of Allah be upon him, saying: "There is nothing for a killer."