Musannaf Ibn Abi Shayba 9:217

Yazid ibn Harun narrated to us, from Habib, from ‘Amr, who said: Jabir ibn Zayd was asked about a man who had a slave woman as his wife, and he divorced her once, then he emancipated the slave woman, and then he bought his wife—what is her status? He said: If he buys her, she is in the status of a concubine. ‘Ikrimah and al-Hasan also issued a legal opinion (fatwa) to that effect.