John Calvin Commentary Genesis 20:1

"And Abraham journeyed from thence toward the land of the South, and dwelt between Kadesh and Shur. And he sojourned in Gerar." — Genesis 20:1 (ASV)

And Abraham journeyed from thence. What Moses related concerning the destruction of Sodom was a digression. He now returns to the continuation of his history and proceeds to show what happened to Abraham; how he conducted himself, and how the Lord protected him; until the promised seed, the future source of the Church, should be born to him.

He also says that Abraham came into the South country; not that he traveled beyond the limits of the inheritance given to him, but that he left his former abode and went towards the South. Moreover, the region which he points out mainly fell, afterwards, to the lot of the tribe of Judah.

It is, however, unknown what his intention was in moving, or what necessity compelled him to change his place. However, we should be persuaded that he had not transferred his abode to another place for any insufficient reason, especially since a son, whom he had not even dared to wish for, had recently been promised to him through Sarah.

Some imagine that he fled from the sad spectacle that was continually before his eyes, for he saw the plain, which had recently seemed so pleasant to the view and so filled with a varied abundance of fruits, transformed into a misshapen chaos. And certainly, it was possible that the whole neighborhood might be affected by the smell of sulfur, as well as tainted with other corruptions, so that people might more clearly perceive this memorable judgment of God.

Therefore, it is not inconsistent with the facts to suppose that Abraham, seeing the place was under the curse of the Lord, was drawn elsewhere by his detestation of it. It is also credible that (as happened to him in another place) he was driven away by the malice and injuries of those among whom he lived.

For the more abundantly the Lord had shown His grace to him, the more necessary it was, in return, for his patience to be exercised, so that he might reflect on his condition as a pilgrim on earth. Moses also expressly declares that he lived as a stranger in the land of Gerar.

Thus we see that this holy family was driven here and there like refuse, while a fixed abode was granted to the wicked. But it is profitable for the pious to be thus unsettled on earth, lest, by setting their minds on a comfortable and quiet dwelling, they should lose the inheritance of heaven.