Charles Ellicott 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)

Abraham journeyed from there. —That is, from Mamre, where he had stayed for so long, and which seems to have continued to be one of his homes. As he had been commanded to traverse the whole land (Genesis 13:17–18), we need not seek reasons for his removal. It was the rule of his life to move from place to place, both because of his cattle and also because in doing so he was taking possession of the country. There were, nevertheless, certain places which were his headquarters, such as Bethel, Mamre, and Beer-sheba.

The south country. —It is a proper name, the Negeb; see Note on Genesis 12:9. For Kadesh, see Genesis 16:14; for Shur, see Genesis 16:7; and for Gerar, see Genesis 10:19.