Leviticus 20:20-23

²⁰And if a man shall lie with his uncle’s wife, he hath uncovered his uncle’s nakedness: they shall bear their sin; they shall die childless.

²¹And if a man shall take his brother’s wife, it is impurity: he hath uncovered his brother’s nakedness; they shall be childless.

²²Ye shall therefore keep all my statutes, and all mine ordinances, and do them; that the land, whither I bring you to dwell therein, vomit you not out.

²³And ye shall not walk in the customs of the nation, which I cast out before you: for they did all these things, and therefore I abhorred them.