Musannaf Ibn Abi Shayba 9:1341

Abu Bakr narrated to us, he said: Abda bin Sulayman narrated to us, from Sa’id, from Abd al-Karim, from Mujahid and Miqsam, from Ibn Abbas, that a slave woman was emancipated, so she chose herself [to be free] before he had consummated the marriage with her. He said: There is nothing for her. It is not agreed upon that she should go with herself and his wealth.