Continuing the response to the meta call for contradiction.
In Genesis Chapter 20 we find the following sister/wife story:
And Abraham journeyed from there to the land of the Negev, and he settled between Kodesh and Shur, and he lived in Gerar. And Abraham said to Sarah his wife, she is my sister; and he sent for Avimelech(Abimelech) the King of Gerar, who took Sarah.
And God came to Abimelech in a dream that night, and said to him, "you will die for the woman you took, she is a husband's wife."
And Abimelech did not become close to her, and said "my Lord, even righteous people will you slay? Because he told me, 'she is my sister', and she also said, 'he is my brother'. With an innocent heart, and with unsullied hands, I did this."
This is a repeat of a sister/wife story in Genesis 12:
And there was hunger in the land; and Abram emigrated down to Egypt to live there, because the hunger in the land was heavy.
And it was, when he was close to going to Egypt; and he said to Sarai, his wife, listen, I know that you are a beautiful woman to look at. And if the Egyptians shall see you, and say, she is this man's wife, then they will kill me, and you they will keep alive. Please say you are my sister, so that it will improve my lot for you, and my soul will survive on cause of you.
And it was, as Abram came to Egypt, and the Egyptians saw the woman, that very beautiful was she. And the ministers of the Pharaoh saw her, and they praised her to Pharaoh; and the woman was taken to the house of the Pharaoh. And to Abraham, he gave favor, for her sake. And he had sheep and cattle, and slaves, and maidservants, and she-mules and camels.
And Yahweh plagued the Pharaoh with great ills, and his household, on account of Sarai, the wife of Abram. And Pharaoh called Abram to say, "what is this you have done onto me? Why did you not tell me that she is your wife? Why did you say she is my sister, and I take her for myself for a wife?; and now, here is your wife, take her and leave." And Pharaoh put men to watch him; and away they sent him and his wife and all that he had.
The narrative mostly repeats, but with the difference that the second version appears after we learn that Abraham has changed his name from Abram at age 99, and Sarah is age 90. Further, we learn that Sarah no longer is fertile, that she has gone through menopause. It is because of this that Isaac's birth is miraculous.
Yet Abimelech takes her for a wife, and the passage explains that he intends to sleep with her, despite her apparent infirmity, until God comes to him in a dream.