(1) יהוה said to Abram, “Go forth from your native land and from your father’s house to the land that I will show you.
(2) I will make of you a great nation,
And I will bless you;
I will make your name great,
And you shall be a blessing.*a blessing I.e., a standard by which blessing is invoked; cf. v. 3 end.
(3) I will bless those who bless you
And curse the one who curses you;
And all the families of the earth
Shall bless themselves by you.”

לך לך GET THEE OUT (literally, go for thyself) — for your own benefit, for your own good: there I will make of you a great nation whilst here you will not merit the privilege of having children (Rosh Hashanah 16b). Furthermore, I shall make known your character throughout the world (Midrash Tanchuma, Lech Lecha 3)

מארצך FROM THY LAND — But had he not already departed from there together with his father and had reached as far as Haran (Genesis 11:31)? But thus God in effect said to him: Go still further away — leave now thy father’s house also.

אשר אראך WHICH I WILL SHOW THEE — He did not reveal to him at once which land it was in order that he should hold it in high esteem and in order to reward him for complying with each and every command. Similar is, (Genesis 22:2) “Take thy son — thine only son — whom thou lovest — even Isaac”; similar is (Genesis 22:2) “upon one of the mountains which I will tell thee of”; similar is, (Jonah 3:2) “And make unto it the proclamation that I shall tell thee of” (Genesis Rabbah 39:9).

ואעשך לגוי גדול AND I WILL MAKE OF THEE A GREAT NATION —Since travelling is the cause of three things—it decreases (breaks up) family life, it reduces one’s wealth and lessens one’s renown, he therefore needed these three blessings: that God should promise him children, wealth and a great name (Genesis Rabbah 39:11).

ומקללך אאור, it is not customary to use the plural mode when speaking of curses. Seeing that there would be very few people, if any, who would curse Avram, this is hinted at in the use of the singular mode in the word ומקללך, “someone who curses you.”

ונברכו בך כל משפחות, all the families of the earth within whose radius Avram would make his residence, such as the land of Canaan, Egypt, and the land of the Philistines, would experience a special blessing due to the proximity of Avram.

ואברכה מברכיך ומקללך אאור, “I will bless those who bless you, and curse those who curse you;” you may question why elsewhere G-d uses the reverse order, i.e. “he who curses you, and I will bless him who blesses you” (Genesis 27,29). The reason for that formulation is that as a general rule, the righteous first experience trials and tribulations in their lives, whereas their relative serenity does not occur until they are well advanced in age.[When Yaakov was well advanced in years and thought the time had come for him to “retire,” according to Rashi in his commentary on Bereshit Rabbah 84,3, he attributes his problem with Joseph to Yaakov expecting worry free life in this world also. Ed.] The answer to the above question is that we must distinguish between who does the blessing and cursing. When the subject is a human being, a righteous person who bestows a blessing, he will commence by mentioning the negative first and the positive as the conclusion (as did Yitzchok when he blessed Yaakov, thinking that Esau was righteous, as in Genesis 27,29) When the subject is G-d Himself, as when G-d blessed Avraham, here, it is more appropriate that He should commence by mentioning the positive aspects first. Furthermore, as generally speaking there are likely to be more people who bless a man such as Avraham, seeing that they are the majority, they are mentioned first, whereas the Torah speaks of מקללך, “he who curses you,” in the singular mode, not “they who curse you,” in the plural mode.ונברכו, a weak conjugation, according to Rash’bam, in the sense of refining through mixing. Through mixing with your descendants many nations will become spiritually uplifted. This is also why the Torah refers here to: משפחות האדמה, “the families on earth.”