Musannaf Ibn Abi Shayba 9:333

Jarir narrated to us, from Mughira, from Ibrahim and 'Amir, regarding a man who had intercourse with his wife's daughter: They both said: "Both of them have become forbidden to him." And Ibrahim said: "They used to say: If a man looks at a woman in a way that is not lawful for him, or touches her with desire, then both of them have become forbidden to him."