Charles Ellicott Commentary Genesis 26:17

"And Isaac departed thence, and encamped in the valley of Gerar, and dwelt there." — Genesis 26:17 (ASV)

The valley of Gerar. —The word nahal, rendered “valley,” means a narrow defile through which a summer torrent flows. In the bed of these streams water can generally be found by digging, and Isaac hoped that he was far enough from the city for the enmity to cease. But he was mistaken, though he seems for a short period to have been left in peace.