Moses
Genesis 26:2BSB·traditional attribution

The LORD appeared to Isaac and said, “Do not go down to Egypt. Settle in the land where I tell you.

John Calvin Reformed @genevareformer

2. And the Lord appeared unto him. I do not doubt but a reason is here given why Isaac rather went to the country of Gerar than to Egypt, which perhaps would have been more convenient for him; but Moses teaches that he was withheld by a heavenly oracle, so that a free choice was not left him.

Matthew Henry Presbyterian @wholebiblehenry

Here, I. God tried Isaac by his providence. Isaac had been trained up in a believing dependence upon the divine grant of the land of Canaan to him and his heirs; yet now there is a famine in the land, Gen 26:1. What shall he think of the promise when the promised land will not find him bread?

Commenting on Genesis 26:1-5

John Gill Reformed Baptist @doctorgill

And the Lord appeared unto him,.... In a vision or dream, when he was at Gerar: and said, go not down into Egypt; as his father had done in the like case, and where Isaac thought to have gone, and the rather, as that was a fruitful country; and so the Targum of Jonathan,"and it was in the heart of Isaac to go down into...