And Abraham sojourned in the Philistines' land many days. Even many years, days being sometimes put for years; having entered into covenant with Abimelech, the king of the country, and settled a good correspondence with him, and having his friendship and good will, which commanded respect from his subjects, Abraham sojourned very quietly and comfortably for many years, chiefly at Beersheba; the Jewish writers say (a) he sojourned here twenty six years.
(a) Jarchi & Bereshit Rabba, sect. 54. fol. 48. 4.

Abraham sojourned in the Philistines' land--a picture of pastoral and an emblem of Christian life.

Abraham sojourned a long time there in the Philistines' land. There Isaac was probably born, and grew up to be a young man (Genesis 22:6), capable of carrying the wood for a sacrifice; cf. Genesis 22:19. The expression "in the land of the Philistines" appears to be at variance with Genesis 21:32, where Abimelech and Phicol are said to have returned to the land of the Philistines. But the discrepancy is easily reconciled, on the supposition that at that time the land of the Philistines had no fixed boundary, at all events, towards the desert. Beersheba did not belong to Gerar, the kingdom of Abimelech in the stricter sense; but the Philistines extended their wanderings so far, and claimed the district as their own, as is evident from the fact that Abimelech's people had taken the well from Abraham. On the other hand, Abraham with his numerous flocks would not confine himself to the Wady es Seba, but must have sought for pasture-ground in the whole surrounding country; and as Abimelech had given him full permission to dwell in his land (Genesis 20:15), he would still, as heretofore, frequently come as far as Gerar, so that his dwelling at Beersheba (Genesis 22:19) might be correctly described as sojourning (nomadizing) in the land of the Philistines.