Kerisos 3:5-6

Krisos 3:5

A single prohibited relationship can obligate a person in six sin offerings. For example, if one has relations with his daughter, he can simultaneously violate the prohibitions against a daughter, a sister, a brother’s wife, a father’s wife, a married woman and a menstruant. (The gemara – Krisos 14b – explains how this situation can come about.) If one has relations with his daughter’s daughter, he can simultaneously violate the prohibitions against a daughter’s daughter, a daughter-in-law, a wife’s sister, a brother’s wife, a paternal uncle’s wife, a married woman and a menstruant. Rabbi Yosi said that if this person’s father married her extralegally, he would additionally be liable for a father’s wife. The same scenario holds true if a person has relations with his wife’s daughter or his wife’s daughter’s daughter.

Krisos 3:6

If a man has relations with his mother-in-law, he can simultaneously be liable for relations with a mother-in-law, a daughter-in-law, a wife’s sister, a brother’s wife, a paternal uncle’s wife, a married woman and a menstruant. The same is true if one has relations with his mother-in-law’s mother or his father-in-law’s mother. Rabbi Yochanan ben Nuri says that if one has relations with his mother-in-law, he can simultaneously be liable for relations with a mother-in-law, a mother-in-law’s mother and a father-in-law’s mother; the Sages replied that these are all parts of the same greater prohibition.