Thematic Bible: Isaac, in calling his wife his sister

Then asked the men of the place as to his wife, and he said, My sister, is she, - For he feared to say My wife, lest said he the men of the place should slay me on account of Rebekah, for fair to Nook on, she is. And it came to pass when the days had lengthened out to him there, that Abimelech king of the Philistines, looked out through the lattice of a window, - and he beheld and lo! Isaac - laughing with Rebekah his wife. So Abimelech called for Isaac, and said, But to she is, thy wife! How then, saidst thou, She is, my sister? And Isaac said unto him, Because, I said, Lest I die on her account.