Thematic Bible: Abraham, in calling his wife his sister

And it happened, when he had come near to enter into Egypt, he said to Sarai his wife, Behold now, I know that you are a beautiful woman to look upon. And it will be when the Egyptians see you, they shall say, This is his wife. And they will kill me, but they will save you alive. I pray you, say that you are my sister, so that it may be well with me for your sake. And my soul shall live because of you. read more.
And it happened when Abram had come into Egypt, the Egyptians saw that the woman was very beautiful. The princes of Pharaoh also 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 he-asses, and male servants, and maidservants, and she-asses, and camels. And Jehovah plagued Pharaoh and his house with great plagues because of Sarai, Abram's wife. And Pharaoh called Abram and said, What is this you have done to me? Why did you not tell me that she is your wife? Why did you say, She is my sister? And so I was about to take her to me as wife. Now therefore behold your wife. Take her and go.

And Abraham said of Sarah his wife, She is my sister. And Abimelech the king of Gerar sent and took Sarah. But God came to Abimelech in a dream by night, and said to him, Behold, you are about to die, for the woman whom you have taken; for she is a man's wife. But Abimelech had not come near her. And he said, Lord, will You also kill a righteous nation? read more.
Did he not say to me, She is my sister? And she, even she herself said, He is my brother. In the sincerity of my heart and innocency of my hands I have done this. And God said to him in a dream, Yes, I know that you did this in the sincerity of your heart. For I also withheld you from sinning against Me. Therefore I did not allow you to touch her. Now therefore, restore his wife to the man. For he is a prophet, and he shall pray for you, and you shall live. And if you do not restore her, know that you shall surely die, you, and all that are yours. And Abimelech rose early in the morning, and called all his servants, and told all these things in their ears. And the men were greatly afraid. Then Abimelech called Abraham, and said to him, What have you done to us? In what have I offended you, that you have brought on me and on my kingdom a great sin? You have done deeds to me that ought not to be done. And Abimelech said to Abraham, What did you see 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 kill me for my wife's sake. And yet truly she is my sister. She is the daughter of my father, but not the daughter of my mother. And she became my wife.