Genesis 20
12 Ref and also, truly she is my sister, daughter of my father, only not daughter of my mother, and she becometh my wife;
13 Ref and it cometh to pass, when God hath caused me to wander from my father's house, that I say to her, This `is' thy kindness which thou dost with me: at every place whither we come, say of me, He `is' my brother.'