Génesis 20:11

Because I thought Lit. "I said": see note on Génesis 18:17.

Surely the fear of God Abraham's defence is that he assumed a heathen people did not fear God; and, therefore, would not be afraid of any Divine retribution, if they took the life of a stranger (gêr). The stranger had no rights; his God would not be known. He would have no "avenger of blood." See note on Génesis 4:15.

See the same idea underlying Joseph's words, "for I fear God"(Génesis 42:18).

they will slay me He does not explain, why he feared that he would be slain for his wife's sake. Obviously it is for the reason mentioned in Génesis 12:12. Sarah's youth and beauty are assumed: the murder of the stranger would enable the inhabitants of Gerar to seize her. For this murder there would be no redress; and, therefore, there would be little compunction.