The 337th prohibition is that one is forbidden from having relations with a woman and her daughter.

The source of this commandment is G‑d's statement,1 "do not commit incest with a woman and her daughter."

One who transgresses this prohibition — i.e., one of them is his wife, and he has relations with the other — and does so intentionally, is punished by s'reifa2 if there is acceptable testimony, in addition to kares.3 If he transgressed unintentionally, he must bring a sin-offering.4