Leviticus 20:17 in the 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.
Context
16 “‘If a woman approaches any animal and lies with it, you shall kill the woman and the animal. They shall surely be put to death. Their blood shall be upon them.
17 “‘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.
18 “‘If a man lies with a woman having her monthly period, and uncovers her nakedness, he has made her fountain naked, and she has uncovered the fountain of her blood. Both of them shall be cut off from among their people.