Genesis 26:19

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

And Isaac digged again the wells of water, which they had digged in the days of Abraham his father; for the Philistines had stopped them after the death of Abraham: and he called their names after the names by which his father had called them.

And the herdmen of Gerar did strive with Isaac's herdmen, saying, The water [is] ours: and he called the name of the well Esek; because they strove with him.

And they digged another well, and strove for that also: and he called the name of it Sitnah.