John Gill Commentary Genesis 20:4

"Now Abimelech had not come near her. And he said, Lord, wilt thou slay even a righteous nation?" — Genesis 20:4 (ASV)

But Abimelech had not come near her

Sarah had been put into an apartment in his palace, and not yet admitted to his company, not at least to his bed; he had not lain with her, which is the design of the expression: the Septuagint version is, "had not touched her", as in ^{(Genesis 20:6)}; which is another phrase expressive of the same thing:

and he said, Lord, wilt thou slay also a righteous nation ?

meaning either his family, the greater part of which were not accessory to this affair; or rather his kingdom, as Aben Ezra, see ^{(Genesis 20:9)}; which though not a nation of righteous men, in a strict sense, see ^{(Genesis 20:11)}; yet with regard to this business of Sarah were no ways criminal:

either God had threatened to destroy his people, as well as himself, if he did not return Sarah to her husband, or committed iniquity with her; or he knew that this had been usual for people to suffer for the crimes of their governors, and like a true father of his country shows an affectionate concern for their welfare in the first place; for this may be the sense of the word "also", on which an emphasis is put; wilt thou not only slay me, but also a whole nation for my sake, a nation free from all fault and blame in this matter? though some think he has reference to the destruction of Sodom and Gomorrah, a recent action, and fresh in his mind; as if he should say, thou hast justly destroyed a wicked people for their sins, and wilt thou also destroy a nation that at least, in comparison of them, is a just and righteous one?