Leviticus 20:17

Whosoever shall take his sister by his father or by his mother, and shall see her nakedness, and she see his nakedness, it is a reproach: they shall be destroyed before the children of their family; he has uncovered his sister's nakedness, they shall bear their sin.

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.

“‘If a man takes his sister—his father’s daughter, or his mother’s daughter—and sees her nakedness, and she sees his nakedness, it is a shameful thing. They shall be cut off in the sight of the children of their people. He has uncovered his sister’s nakedness. He shall bear his iniquity.