Thematic Bible: Isaac, in calling his wife his sister

And when he was questioned by the men of the place about his wife, he said, She is my sister; fearing to say, She is my wife; for, he said, the men of the place may put me to death on account of Rebekah; because she is very beautiful. And when he had been there for some time, Abimelech, king of the Philistines, looking through a window, saw Isaac playing with Rebekah his wife. And he said to Isaac, It is clear that she is your wife: why then did you say, She is my sister? And Isaac said, For fear that I might be put to death because of her.