John Gills Exposition of the Bible Commentary - Genesis 20:1
And Abraham journeyed from thence towards the south country ,.... He returned from the plains or oaks of Mamre, where he had lived fifteen or twenty years, into the more southern parts of the land of Canaan: the reason of this remove is not certain; some think, because he could not bear the stench of the sulphurous lake, the cities of Sodom and Gomorrah were become; and others, because of the scandal of Lot's incest with his daughters, which prejudiced the idolatrous people in those parts... read more
Matthew Henry's Complete Commentary - Genesis 20:1-2
Here is, 1. Abraham's removal from Mamre, where he had lived nearly twenty years, into the country of the Philistines: He sojourned in Gerar, Gen. 20:1. We are not told upon what occasion he removed, whether terrified by the destruction of Sodom, or because the country round was for the present prejudiced by it, or, as some of the Jewish writers say, because he was grieved at Lot's incest with his daughters, and the reproach which the Canaanites cast upon him and his religion, for his... read more