It is narrated from Sayyiduna al-Miswar bin Makhramah (may Allah be pleased with him) that Sayyiduna Umar (may Allah be pleased with him) consulted the people about a woman's miscarriage (caused by a blow), and Sayyiduna al-Mughirah bin Shu'bah (may Allah be pleased with him) said: "I witnessed the Messenger of Allah (peace and blessings be upon him) judging that a ghurrah (a male or female slave) be given." Sayyiduna Umar (may Allah be pleased with him) asked: "Can you bring someone to testify with you?" So Muhammad bin Maslamah (may Allah be pleased with him) testified for him.
Hadith Referenceالمعجم الكبير للطبراني / باب الميم / 17985