Musannaf Ibn Abi Shayba 9:1397

Humaid ibn Abd al-Rahman narrated to us, from Hasan, from Mutarrif, from a man, from Ibrahim, regarding a woman who made her slave-girl lawful for a man, and she bore a child from him. Ibrahim said: "This is a private part he approached out of ignorance, so attach the child to him, and give to this [woman] her slave-girl."