Musannaf Ibn Abi Shayba 18:555

Abu Bakr narrated to us, he said: Waki’ narrated to us, from Sufyan, from Jabir, from ‘Amir, who said regarding the fetus (in the womb): "For every fetus, there is a *ghurra* (compensation of a slave)." He said: And Al-Hakam said regarding it: "It is a matter of settlement until its creation becomes manifest." Waki’ said: And the statement of Al-Hakam is better than the statement of Al-Sha’bi.