Genesis 26:1

1Now there was a famine in the land [of Canaan], besides the previous famine that had occurred in the days of Abraham. So Isaac went to Gerar, to 26:1 This is not the Abimelech of ch 20. Abimelech may actually be a dynastic title, like Caesar or Pharaoh, instead of a proper name. The events recounted in chapters 20 and 26 are separated by almost a hundred years.Abimelech king of the Philistines.