Leviticus 20:17-22

¹⁷And if a man takes his sister, daughter of his father or his mother, and has sex relations with her and she with him, it is an act of shame: they are to be cut off before the children of their people; he has had sex relations with his sister, and his sin will be on him.

¹⁸And if a man has sex relations with a woman at the time when she is unwell, he has seen her fountain and she has let the fountain of her blood be uncovered, and the two of them are to be cut off from among their people.

¹⁹And you may not have sex connection with your mother's sister or your father's sister, for they are his near relations: their sin will be on them.

²⁰And if a man has sex relations with the wife of his father's brother, he has put shame on his father's brother: their sin will be on them; till the day of their death they will have no children.

²¹And if a man takes his brother's wife, it is an unclean act; he has put shame on his brother; they will have no children.

²²So then, keep my rules and my decisions and do them, so that the land which I am giving you as your resting-place may not violently send you out again.