Then Abram fell on his face; and God said to him,
4 "As for me, this is my covenant with you. You shall be the ancestor of a multitude of nations.
5 No longer shall your name be Abram, but your name shall be Abraham; for I have made you the ancestor of a multitude of nations.
6 I will make you exceedingly fruitful; and I will make nations of you, and kings shall come from you."
from Zornberg (Beginning of Desire p. 76) a comment on an earlier part of the text in Genesis, but looking forward to a "new kind of nation":
"Sarai was barren" — the barrenness of Sarai evokes the other meaning of the wordakara: the couple is uprooted, the ground cut from under their feet. Voluntarily, they respond to a call to alienation from all that gives self placement in the world. By removing themselves from the normal conditions of fruitfulness, they — at least on the face of things — cut off vital sources of nourishment, doom themselves to a sterile nomadic existence, in which no organic fibers of connection and fertility can grow.
That is why, according to Rashi (12:1), the blessings that follow immediately on the call oflekh lekha are so necessary and so paradoxical. The divine command thrusts Abram and Sarai into the eye of the storm, takes the problem ofakarut (barrenness) and has them act out all the meanings of deracination, of disconnection from a succession of pasts.
An act of radical discontinuity is, it seems, depicted in the Torah as the essential basis for all continuity: for that act of birth that will engender the body and soul of a new kind of nation. …