Genesis 26:7-9

7When the men of the place asked about his wife, he said, “1She is my sister,” for he was 2afraid to say, “my wife,” thinking, “3the men of the place might kill me on account of Rebekah, since she is 4beautiful.”

8Now it came about, when he had been there a long time, that Abimelech king of the Philistines looked down through a window, and saw them, and behold, Isaac was caressing his wife Rebekah.

9Then Abimelech called Isaac and said, “Behold, she certainly is your wife! So how is it that you said, ‘She is my sister’?” And Isaac said to him, “Because I thought, ‘otherwise I might be killed on account of her.’”