Genesis 12:13

Say thou art my sister: so she was, either,

1. More generally, as his niece; for nephews and nieces are in Scripture called brethren and sisters, as Genesis 13:8. Or rather,

2. Properly, i.e. by the father's side, Genesis 20:12. So this expression was true, but ambiguous, and intended to deceive the Egyptians, and therefore unwarrantable. And here Abram, the father of the faithful, elsewhere celebrated for the strength of his faith, betrays his infirmity and distrust of God's providence and promise, and this fact was not without great danger both to himself and Sarai.