Musannaf Ibn Abi Shayba 9:650

Ghundar narrated to us, from Shu'bah, who said: I asked al-Hakam about a man who had a wife, and she was emancipated. He then had intercourse with her after the emancipation, and she said, "I did not know that I had a choice [to remain or leave]." He said: She is to be made to swear an oath that she did not know she had a choice, then she is given the choice. And I asked Hammad, and he said: She is his wife, and she is not given a choice.