John Calvin Commentary Genesis 28:14

"And thy seed shall be as the dust of the earth, and thou shalt spread abroad to the west, and to the east, and to the north, and to the south. And in thee and in thy seed shall all the families of the earth be blessed." — Genesis 28:14 (ASV)

And thy seed shall be as the dust of the earth. The sum of the whole is this: whatever the Lord had promised to Abraham, Jacob transmitted to his sons. Meanwhile, it was fitting for the holy man, in reliance on this divine testimony, to hope against hope; for though the promise was vast and magnificent, yet, wherever Jacob turned, no ray of good hope shone upon him.

He saw himself a solitary man; no condition better than that of exile presented itself; his return was uncertain and full of danger. But it was profitable for him to be thus left destitute of all means of help, so that he might learn to depend on the word of God alone.

Thus, at the present time, if God freely promises to give us all things, and yet seems to approach us empty-handed, it is still proper that we should pay such honor and reverence to his word, so that we may be enriched and filled with faith.

Eventually, indeed, after the death of Jacob, the outcome declared how effective this promise had been. By this example, we are taught that the Lord by no means disappoints his people, even when he defers granting those good things which he has promised, until after their death.

And in thee, and in thy seed, shall all the families of the earth be blessed. This clause has greater weight because in Jacob and in his seed the blessing is to be restored from which the whole human race had been cut off in their first parent.

But what this expression means, I have explained above: namely, that Jacob will not only be an exemplar, or formula of blessing, but its fountain, cause, or foundation. For though a certain exquisite degree of happiness is often signified by an expression of this kind, yet, in many passages of Scripture, it means the same as to desire from anyone his blessing and to acknowledge it as his gift.

Thus people are said to bless themselves in God when they acknowledge him as the author of all good. So here God promises that in Jacob and his seed all nations shall bless themselves, because no happiness will ever be found except what proceeds from this source. That, however, which is peculiar to Christ, is appropriately transferred to Jacob, in whose loins Christ then was.

Therefore, since Jacob, at that time, represented the person of Christ, it is said that all nations are to be blessed in him. But, seeing that the manifestation of so great a benefit depended on another, the expression in thy seed is immediately added by way of explanation.

That the word 'seed' is a collective noun forms no objection to this interpretation (as I have said elsewhere). For since all unbelievers deprive themselves of honor and grace, and are thus considered strangers, it is necessary to refer to the Head so that the unity of the seed may appear.

Whoever will reverently ponder this will easily see that, in this interpretation, which is that of Paul, there is nothing tortuous or constrained.