John Calvin Commentary Genesis 12:2

"and I will make of thee a great nation, and I will bless thee, and make they name great; and be thou a blessing;" — Genesis 12:2 (ASV)

And I will make of you a great nation. Until now, Moses has related what Abram had been commanded to do; now he adds the promise of God to the command, and that for a significant reason. For as we are slow to obey, the Lord would command in vain unless we are motivated by an added confidence in His grace and blessing.

Although I have alluded to this before, in the history of Noah, it will not be useless to emphasize it again, for the passage itself requires some comment; and the repetition of a doctrine of such great importance should not seem unnecessary. For it is certain that faith cannot stand unless it is founded on the promises of God.

But faith alone produces obedience. Therefore, so that our minds are inclined to follow God, it is not sufficient for Him simply to command what He pleases unless He also promises His blessing. We must note the promise that Abram, whose wife was still barren, should become a great nation.

This promise might have been very effective if God, by the actual state of things, had given reason for hope for its fulfillment. But now, seeing that the barrenness of his wife threatened him with being permanently without offspring, the bare promise itself would have been unconvincing if Abram had not completely depended upon the word of God. Therefore, though he perceived the barrenness of his wife, he yet grasped by hope that great nation which is promised by the word of God.

Isaiah greatly praises this act of favor, that God, by His blessing, increased His servant Abram—whom He found alone and solitary—to so great a nation (Isaiah 2:2). The noun גוי (goi), “my nation” (Genesis 12:4), though detestable to the Jews, is in this place, and in many others, taken as a term of honor. It is used here emphatically to show that Abram would not only have numerous descendants from his own line, but a special people, separated from others, who would be called by his own name.

I will bless you. This is partly added to explain the preceding sentence. For, so that Abram would not despair, God offers His own blessing, which was able to accomplish more miraculously than is usually accomplished by natural means. The blessing, however, pronounced here extends further than to offspring; and implies that he would have a prosperous and joyous outcome in all his affairs, as appears from the following context: And will make your name great, and you shall be a blessing.

For such happiness is promised him that will fill everyone everywhere with admiration, so that they will introduce the name of Abram as an example into their formulas for pronouncing blessings. Others use the term in the sense of augmentation: You shall be a blessing, that is, ‘All shall bless you.’ But the former sense is more fitting.

Some also explain it actively, as if it had been said, ‘My grace shall not reside in you, so that you alone may enjoy it, but it shall flow far to all nations. I therefore now so deposit it with you, that it may overflow into all the world.’ But God does not yet proceed to that communication, as I shall show shortly.