Genesis 20 - Dummelow's Commentary on the Bible

Abraham at Gerar

1. Abraham leaves Mamre (Hebron) for Gerar, SW. of Philistia. It seems from Genesis 21:34 that he remained in that district for some years.

She is my sister] Twenty years earlier Abraham had used the same device in Egypt and now again he incurs a rebuke from one outside the Covenant. See Genesis 12:11-20 and notes. Abimelech] perhaps, 'Molech is my father,' in honour of the false god. Cp. Abijah, 'Jehovah is my father.'

Wilt thou slay also a righteous nation] Abimelech's people, at all events, had not been guilty of any sin.

In the integrity of my heart] Abimelech was 'not consciously violating any of his own rules of morality.' Had he known that Sarah was Abraham's wife he would not have taken her into his harem.

He is a prophet] i.e. one to whom God reveals His will, and who in turn declares it to men; and so one who can mediate between God and man, as in this case: see on Exodus 7:1.

11-13. Abraham explains that he was only following an arrangement made with his wife when they first came among the licentious Canaanites.

Cp. Genesis 12:13. Sarah was daughter of Terah by another wife, and so was halfsister to Abraham. It is thought that these marriages between relatives in early days were partly intended to keep the blood of the family or tribe pure and unmixed.

Thy brother] ironical. Behold, he is, etc.] RV 'Behold, it is for thee a covering of the eyes to all that are with thee; and in respect of all' (MG or, 'before all men') 'thou art righted.' Apparently this means that the gift was to render those with Sarah willing to overlook the wrong to which she had been exposed.