Genesis 26:17

And Isaac departed thence, and pitched his tent in the valley of Gerar, and dwelt there.

Isaac departed ... and pitched his tent in the valley of Gerar - [Hebrew, nachal (H5158), a torrent and a torrent-bed, a wady; Septuagint, en tee pharangi Geraroon] The whole of the southern frontier of Palestine, called the Negeb or 'south country,' consisting of vast undulating plains, which extend between the hills of Judah and the desert of Sinai, were neutral ground, on the natural pastures of which the patriarchs fed their large flocks, before they had obtained a permanent abode. The valley of Gerar-now Wady el-Jerur-about 50 miles south of the city Gerar, is perhaps the remote extremity of that pasture land. That the Wady el-Jerur is not without its attractions as a place of resident and that its immediate neighbourhood, partly arable and party pastoral, was well adapted for an ancient settlement, is evident from the testimony of Dr. Robinson, who says, 'This whole basin was full of shrubs and vegetation, and seemed capable of tillage. Indeed, in several spots we saw traces of rude plowing, and were told that in years of rain the Arabs are accustomed to plow and sow here. A thin, meagre grass was springing up in various places. At another point in Wady el-Jerur vegetation seemed more abundant, and camels were at pasture' (Wilton's 'Negeb').