Genesis 20:2

She is my sister See notes on Genesis 12:13. It seems almost incredible that, after the event recorded in Genesis 12:13-20, Abraham should once again have displayed the same faults of cowardice and dissimulation. Sarah also is advanced in years; and, in Genesis 18:10-14, had received the promise of a son. The narrative most probably is a duplicate of the tradition of Genesis 12:13-20. Its present position, between the promise of a son in Genesis 18:10-14, and its fulfilment in chap. 21, becomes intelligible on the supposition of its derivation from an independent source, not connected with chap. 18.

Abimelech i.e. "my father is Melech." This is probably a name compounded with that of a Canaanite deity, Milk (Molech in the English Bible).