Musnad Ahmad 626:80

Waki’ narrated to us, Hisham ibn ‘Urwah narrated to us, from his father, from al-Miswar ibn Makhramah, who said: ‘Umar ibn al-Khattab consulted the people regarding the miscarriage of a woman. Al-Mughirah ibn Shu’bah said: "I witnessed the Messenger of Allah, peace and blessings of Allah be upon him, judge regarding it with a *ghurrah* (a compensation): a male slave or a female slave." ‘Umar said: "Bring me someone who will testify with you." He said: So Muhammad ibn Maslamah testified for him.