John Gill Commentary Genesis 26:16

"And Abimelech said unto Isaac, Go from us. For thou art much mightier than we." — Genesis 26:16 (ASV)

And Abimelech said to Isaac, go from us
Which was either said by way of advice, consulting Isaac's good, and the peace of his own kingdom; or else by way of command, enjoining him to depart, having a secret envy to him himself, or at least was jealous of his growing power and wealth: for you are much mightier than we ;
in riches or goods, as the Targum of Jonathan adds; or in number; his family being greatly increased, his servants numerous, many being born of them in his house; Abraham had three hundred and eighteen trained servants in his house, (Genesis 14:14) ; how many Isaac has is not certain; they must be a large number for Abimelech to fear anything from them. Some choose to interpret the words, you have increased, or you have got much from us, and by us; and therefore it is high time for you to be gone from us.