Leviticus 20:17

Whoever will have taken his sister, the daughter of his father or the daughter of his mother, and will have seen her nakedness, and she will have looked upon her brother’s shame, they have committed a nefarious act. They shall be slain in the sight of their people, because they have uncovered one another’s nakedness. And they shall bear their iniquity

Other versions

King James Version

And if a man shall take his sister, his father's daughter, or his mother's daughter, and see her nakedness, and she see his nakedness; it is a wicked thing; and they shall be cut off in the sight of their people: he hath uncovered his sister's nakedness; he shall bear his iniquity.

English Standard Version

"If a man takes his sister, a daughter of his father or a daughter of his mother, and sees her nakedness, and she sees his nakedness, it is a disgrace, and they shall be cut off in the sight of the children of their people. He has uncovered his sister's nakedness, and he shall bear his iniquity.

New International Version

"'If a man marries his sister, the daughter of either his father or his mother, and they have sexual relations, it is a disgrace. They must be cut off before the eyes of their people. He has dishonored his sister and will be held responsible.