Musannaf Ibn Abi Shaybah 17052 — A man who marries a woman

Muslim bin Uwaymir of Banu Bakr bin Kinanah said: My father married me to a woman in Taif. I had not yet had intercourse with her when my uncle, who was her mother's husband, died. Her mother was a wealthy woman. My father said to me: "If you were to marry her mother, it would be very good." I said: "I would like that, but how, when I have married her daughter?" Then I asked Sayyiduna Ibn Abbas (may Allah be pleased with them both) about this, and he said: "Marry her."