Maliks Muwatta Book 28, Hadith Number 33.

Section : Reprehensibility of Intercourse with Two Sisters or a Mother and Daughter that One Owns.

Yahya related to me from Malik from Ibn Shihab from Ubaydullah ibn Abdullah ibn Utba ibn Masud from his father that Umar ibn al-Khattab was asked about a woman and her daughter who were in the possession of the right hand, and whether one could have intercourse with one of them after the other Umar said, “I dislike both being permitted together.” He then forbade that.