Musnad Ahmad 626:44

'Abd al-Rahman narrated to us, from Sufyan. And Zayd ibn al-Hubab narrated to us, Sufyan informed us—the meaning being the same—from Mansur, from Ibrahim, from 'Ubayd ibn Nadilah—Zayd said: al-Khuza'i—from al-Mughirah ibn Shu'bah, that two co-wives, one of them struck the other with a tent pole, and killed her. The Messenger of Allah, peace and blessings of Allah be upon him, decreed the blood money (diyah) upon the paternal relatives ('asabah) of the killer, and for what was in her womb, a slave (ghurrah). The Bedouin said: "Shall I pay a fine for one who neither ate, nor drank, nor cried out, and so died? Such a claim is void." The Messenger of Allah, peace and blessings of Allah be upon him, said: "He rhymes like the rhyming of the Bedouins, yet for what is in her womb, there is a slave."