Genesis 26:2-5

And the LORD appeared unto him, and said, Go not down into Egypt; dwell in the land which I shall tell thee of:

And the Lord appeared unto him. This was the first divine communication made to Isaac personally. It had been previously announced to Abraham that Isaac was to be his sole heir; and now that, on the death of his father, he had succeeded to the patrimonial inheritance, he was to receive also a renewal of the divine promise which guaranteed special blessings of inestimable value to him and his posterity. The covenant securing these blessings originated entirely in divine grace; but it was suspended on the condition that Abraham should walk before God and be perfect (Genesis 17:1): and since he had, through the grace which had enabled him to attain an extraordinary strength of faith, fully met that condition by an obedience honoured with the strongest expression of divine approval,-Isaac, his son, was now assured that the covenant would progressively take effect, the assurance being made doubly sure to him by a reference to the oath sworn to Abraham (Genesis 22:16). The first installment of this promise was the possession of Canaan, here designated "all these countries," from its numerous subdivisions among the petty tribes which then occupied the land (Genesis 15:19-21); and in prospect of this promissory tenure of the land, Isaac was prohibited leaving it. The prohibition was doubtless dictated by unerring wisdom; and although it may be impossible to penetrate all the grounds for it, one reason in all probability arose from the personal character of Isaac, who was a man of weaker faith than Abraham, and consequently would have been less able to resist the temptation of a permanent settlement in that fertile country. At all events, now that the Abrahamic covenant had to be executed, the elect family were not henceforth allowed to go into Egypt, except with the special sanction and under the immediate superintendence of an overruling Providence.