Jamieson, Fausset and Brown on Genesis 26:18-22

18-22. Isaac digged again the wells of water--The naming of wells by Abraham, and the hereditary right of his family to the property, the change of the names by the Philistines to obliterate the traces of their origin, the restoration of the names by Isaac, and the contests between the respective shepherds to the exclusive possession of the water, are circumstances that occur among the natives in those regions as frequently in the present day as in the time of Isaac.