Genesis 26:14-17

and he had possessions of flocks, and possessions of herds, and a great household: and the Philistines envied him. Now all the wells which his father’s servants had digged in the days of Abraham his father, the Philistines had stopped, and filled with earth. And Abimelech said unto Isaac, Go from us; for thou art much mightier than we. And Isaac departed thence, and encamped in the valley of Gerar, and dwelt there.