Musannaf Ibn Abi Shayba 13:676

Abu Bakr narrated to us, he said: Abu Dawud al-Tayalisi narrated to us, from Abd al-Aziz ibn Muslim, from Ibn Abi Najih, from Ata, Tawus, Mujahid, and Sa'id ibn Jubayr, that they said: The child of the *mudabbarah* (a slave woman whose freedom is promised upon the death of her master) is in the same status as their mother.