Permissibility of sexual intercourse with one of two sisters owned by a man simultaneously.
Chapter on What is Prohibited to Marry and Combining Between Them and Other Matters
Al-Mughni
Book of Marriage
Primary text
Intercourse is permissible with one of the two sisters in the possession of a man, according to the opinion of the majority of scholars. The evidence for this ruling is that the man is not combining them on the bedding (in intimacy), which means it is not prohibited, analogous to the situation where he owns only one of them.
Supporting text
Al-Hakam and Hammad stated that one should not approach either of the two sisters. This view is also narrated from Al-Nakha'i, and Abu Al-Khattab mentioned it as a position held by Ahmad.