Genesis 20:2, 5, 12-13

Abraham introduced his wife, Sarah, by saying, “She is my sister.” So King Abimelech of Gerar sent for Sarah and had her brought to him at his palace.

Didn’t Abraham tell me, ‘She is my sister’? And she herself said, ‘Yes, he is my brother.’ I acted in complete innocence! My hands are clean.”

And she really is my sister, for we both have the same father, but different mothers. And I married her. When God called me to leave my father’s home and to travel from place to place, I told her, ‘Do me a favor. Wherever we go, tell the people that I am your brother.’”