The first book of the Torah paints a broad story arc for the development of relationships, including within marriage, between parents and children, and between man and G-d.
There is another facet to this growth as well: the development of mankind’s ability to control ourselves, instead of being led by our emotions and desires.
To bring just one illustrative example: G-d tries to instruct Cain:
G-d said to Cain:
Why are you upset? Why has your face fallen? Is it not that if you intend good, carry it? But if you do not intend good, at the entrance crouches (rovetz) sin [broadly: natural desires to dominate or harm], Desiring you – but you can rule over him.
We know how that played out. Cain chose to be ruled by his instinctive jealousy and anger, and he killed his brother. Which is natural enough in the animal kingdom – even G-d says so, when He says (G. 6:5): The LORD saw how great was man’s wickedness on earth, and how every desire of his heart was nothing but evil all the time.
That may indeed be our nature. But we are supposed to rise above our natures! The word rovetz, used to describe sin “crouching” at the door, is almost exclusively used in the Torah to describe the behavior of an animal. We are supposed to be better than mere animals.
Rovetz is used once again to describe Judah, in Jacob’s blessing. Why? Because with both Tamar and Joseph, Judah acts deliberately and consciously, not giving in to his instincts or pride. Jacob says so in his blessing to Judah: “from torn-animal [the goat-blood on Joseph’s coat], my son, you have gone up!” Judah grows into the archetypal leader. Jacob’s blessing includes the word rovetz, “crouching.”
Joseph also grows, and shows the growth through Genesis. Joseph controls his urges with Potiphar’s wife, and he does the same when he sees his brothers. Instead of having them killed, or acting out of baser instincts, Joseph takes his time. He probes the situation and seeks to learn and understand the true situation before revealing himself. Joseph acts with thought and care, and ultimately with consideration and even love. What a contrast to Cain’s violence toward Abel!
Hence Jacob (and later Moshe) both bless Joseph with rovetz, “crouching” blessings. Why? I think it is to show how much people can grow past the behavior of Cain!
Both Judah and Joseph do precisely what Cain failed to do: master the natural urge to sin. And the Torah compares them directly by using the word rovetz, “crouch” in all three cases.
Genesis begins with brothers who act out from their anger. And it ends with brothers who choose thoughtful consideration instead. Connected to each other by this single word, rovetz.