Sahih al-Bukhari 7317, 7318

'Urwa related that al-Mughira ibn Shu'ba said, "'Umar ibn al-Khattab asked about the case of a woman who had a miscarriage because of a blow to the stomach. He said, 'Which of you has heard something from the Prophet, may Allah bless him and grant him peace, on it?' I answered, 'I have.' He asked, 'So what is it?' I said, 'I heard the Prophet, may Allah bless him and grant him peace, say, "She is owed a good slave, male or female."' 'Umar said, 'do not leave until you bring someone who will testify to what you said.' I went out and found Muhammad ibn Maslama. I brought him and he testified with me that he had heard the Prophet, may Allah bless him and grant him peace, say, "She is owed a good slave, male or female."'" Ibn Abi'z-Zinad corroborated it from his father from 'Urwa from al-Mughira.