Genesis 46:3

And he said, I [am] God, the God of thy father,.... His father Isaac, who was now dead, and who is the rather mentioned, because in him Abraham's seed was to be called, and in his line the promise both of the land of Canaan, and of the Messiah, ran, and from him Jacob received the blessing; and this might be a confirmation of it to him, in that Jehovah calls himself his God; he first declares himself to be his God, and so able to perform whatever he should promise him, and his father's God, who would show him favour, as he had to him:

fear not to go down into Egypt; Jacob might have many fears arise in his mind about this journey, as interpreters generally observe; as lest it should not be agreeable to the will of God, since his father Isaac was forbidden to go into Egypt, when in like circumstances with him,

Genesis 26:1; as well as he, might fear it would be too great a journey for him in his old age, some evil would befall him, or he die by the way and not see his son; or lest going with his family thither, and there continuing for some time, they might be tempted with the pleasantness and fruitfulness of the land, and settle there, and forget and neglect the promised land of Canaan; and especially lest they should be drawn into the idolatry of the Egyptians, and forsake the worship of the true God; and very probably he might call to mind the prophecy delivered to Abraham, of his seed being strangers and servants, and afflicted in a land not theirs for the space of four hundred years, Genesis 15:13; and Jacob might fear this step he was now taking would bring on, as indeed it did, the completion of this prediction, by which his offspring would be oppressed and diminished. The Targum of Jonathan makes this to be Jacob's principal fear;

"fear not to go down into Egypt, because of the business of the servitude decreed with Abraham;''

as also he might fear his going thither might seem to be a giving up his title to, and expectation of the promised land: to remove which fears the following is said,

for I will there make of thee a great nation: as he did; for though in process of time his seed were greatly afflicted here, yet the more they were afflicted, the more they multiplied; and their increase in Egypt was vastly greater than it had been in a like space of time before; for in the space of two hundred fifteen years before their descent into Egypt, they were become no more than seventy persons, whereas in the like number of years in Egypt, they became 600,000, besides children; see Genesis 46:27 Exodus 12:37.