And I will bless thee and make thy name great, and be thou a blessing (Gen. 12:2). And I will bless thee implies: I Myself will bless thee. I will make thy name great indicates that your name will be exalted throughout the world. What do the words and be thou a blessing signify? They signify that your blessing will precede My blessing. That is why (in the Amidah prayer) the passage “Shield of Abraham” precedes the prayer “Revive the Dead.” Another comment on Be thou a blessing. The Holy One, blessed be He, said to him: From the time I created My world, I had to bless My creatures. I blessed Adam and Eve, as it is written: And He blessed them (ibid. 1:28), and Noah and his sons, as it is said: And God blessed Noah and his sons (ibid. 9:1), but henceforth, you shall confer blessings.
Scripture says elsewhere And the souls that they made in Haran (Gen. 12:5). R. Alexandri stated: The fact is that if all mankind assembled to make just one mosquito, they would not be able to do so. What then is the meaning of this verse, And the souls that they made in Haran? It means that he taught them about the fear of heaven and instructed them in the law (in that place). The Holy One, blessed be He, said to him: You have sown righteousness and have made Me known in this world, hence you will be rewarded, as it is said: Thy reward shall be exceedingly great (Gen. 16:1).
