John Calvin Commentary Genesis 48:21

"And Israel said unto Joseph, Behold, I die: but God will be with you, and bring you again unto the land of your fathers." — Genesis 48:21 (ASV)

And Israel said unto Joseph. Jacob repeats what he had said. Indeed, all his sons, and especially Joseph and his sons, required something more than one simple confirmation, so that they would not make their home in Egypt, but would dwell, in their minds, in the land of Canaan.

He mentions his own death to teach them that the eternal truth of God did not at all depend on the life of men. It is as if he had said, "My life, since it is short and fading, passes away; but the promise of God, which has no limit, will flourish even when I am dead." No vision had appeared to his sons, but God had ordained the holy old man as the intermediary sponsor of His covenant. He therefore diligently fulfills the duty entrusted to him, taking timely precautions so that their faith would not be shaken by his death.

So, when the Lord delivers His word to the world through mortal men, although they die, having finished their course of life according to the flesh, yet the voice of God is not extinguished with them, but gives us life even today. Therefore Peter writes that he will endeavor, so that after his death, the Church may be mindful of the doctrine committed to him (2 Peter 1:15).

Unto the land of your fathers. It is with good reason that he claims for himself and his fathers dominion over that land where they had always wandered as strangers. For although it might seem that the promise of God had failed, he encourages his sons to a good hope, and pronounces, with a courageous spirit, that land to be his own—a land in which, in the end, he scarcely obtained a burial place, and that only by favor. From where, then, did this great confidence come, except from his desire to accustom his sons, by his example, to have faith in the word of God?

Now this teaching also applies to us, because we never rely with sufficient firmness on the word of God as long as we are led by our own feelings. Indeed, until our faith rises to take hold of those things that are far removed, we do not know what it is to set our seal to the word of God.