Thematic Bible: Abraham, in calling his wife his sister

And it came to pass, when he came near to enter into Egypt, that he said unto Sarai his wife, Behold now, I know that you are a fair woman to look upon: Therefore it shall come to pass, when the Egyptians shall see you, that they shall say, This is his wife: and they will kill me, but they will save you alive. Say, I pray you, that you are my sister: that it may be well with me for your sake; and my soul shall live because of you. read more.
And it came to pass, that, when Abram came into Egypt, the Egyptians beheld the woman that she was very fair. The princes also of Pharaoh saw her, and commended her before Pharaoh: and the woman was taken into Pharaoh's house. And he treated Abram well for her sake: and he had sheep, and oxen, and male donkeys, and menservants, and maidservants, and female donkeys, and camels. And the LORD afflicted Pharaoh and his house with great plagues because of Sarai Abram's wife. And Pharaoh called Abram, and said, What is this that you have done unto me? why did you not tell me that she was your wife? Why did you say, She is my sister? so I might have taken her to me as a wife: now therefore behold your wife, take her, and go your way.

And Abraham said of Sarah his wife, She is my sister: and Abimelech king of Gerar sent, and took Sarah. But God came to Abimelech in a dream by night, and said to him, Behold, you are but a dead man, for the woman that you have taken; for she is a man's wife. But Abimelech had not come near her: and he said, Lord, will you slay also a righteous nation? read more.
Said he not unto me, She is my sister? and she, even she herself said, He is my brother: in the integrity of my heart and innocence of my hands have I done this. And God said unto him in a dream, Yea, I know that you did this in the integrity of your heart; for I also have kept you from sinning against me: therefore I permitted you not to touch her. Now therefore restore the man his wife; for he is a prophet, and he shall pray for you, and you shall live: and if you restore her not, know that you shall surely die, you, and all that are yours. Therefore Abimelech rose early in the morning, and called all his servants, and told all these things in their ears: and the men were much afraid. Then Abimelech called Abraham, and said unto him, What have you done unto us? and how have I offended you, that you have brought on me and on my kingdom a great sin? you have done deeds unto me that ought not to be done. And Abimelech said unto Abraham, What was your thinking, that you have done this thing? And Abraham said, Because I thought, Surely the fear of God is not in this place; and they will slay me for my wife's sake. And yet indeed she is my sister; she is the daughter of my father, but not the daughter of my mother; and she became my wife.