The nakedness of thy sister, the daughter of thy father, or daughter of thy mother, whether she be born at home, or born abroad, even their nakedness thou shalt not uncover.
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.
Cursed be he that lieth with his sister, the daughter of his father, or the daughter of his mother. And all the people shall say, Amen.
2 Samuel 13:11-14
And when she had brought them unto him to eat, he took hold of her, and said unto her, Come lie with me, my sister.
And she answered him, Nay, my brother, do not force me; for no such thing ought to be done in Israel: do not thou this folly.
And I, whither shall I cause my shame to go? and as for thee, thou shalt be as one of the fools in Israel. Now therefore, I pray thee, speak unto the king; for he will not withhold me from thee.
Howbeit he would not hearken unto her voice: but, being stronger than she, forced her, and lay with her.
And one hath committed abomination with his neighbour's wife; and another hath lewdly defiled his daughter in law; and another in thee hath humbled his sister, his father's daughter.