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."

"From thence ..." does not refer to the cave of Lot and his two daughters, but to the residence of Abraham at Mamre. This Biblical example of picking up antecedents removed from the immediate context is common, and the appearance of it here is no excuse for alleging "a variant source" for these words.

"And he sojourned in Gerar ..." The abbreviated narrative here actually means that while Abraham was in the area near the border of Egypt (Kadesh and Shur), that he also made an excursion northward to the Philistine city of Gerar in the south portion of Canaan. T. C. Mitchell of the British Museum assures us that this was:

"A Philistine city, identified with Tell Abu Hureira, a mound about 11 miles southeast of Gaza. It was populated during every period of the Bronze and Iron Ages, with indications of a prosperous period during the Middle Bronze Age, the age of the patriarchs."[4]

Speculations as to why Abraham decided to leave Mamre include the following:

1. He was apprehensive for the safety of that part of the world which had just seen the destruction of the cities of the Plain.
   
2. He was just naturally a wanderer.
   
3. He was seeking better pastures for his flocks and herds.
   
4. He sought to avoid any conflict with the changed populations in the vicinity of Mamre. Of course, no one really knows, but Aalders pointed out that, "The Hittites about this time made deep inroads into southern Canaan, which may have included the area around Hebron."[5] Such an emergency might have led to Abraham's migration.