Genealogies allow an historical writer to cover a large amount of territory, continuing the story, making a few quick but important points along the way as the author moves to the next main subject.
Jacob’s blessing of his sons amounts to a genealogy of sorts, dealing with the past and future of Jacob’s sons and their descendants.
Why wasn’t Reuben, Jacob’s eldest child, the son of promise – the one with the most inheritance? Jacob’s blessing explains that it was the behavior of the first three boys that cost them their place of prominence. As Jacob moves from son to son, he shows that he knows his boys well: their strengths and weaknesses. He has an idea of what will become of each of them.
The wise parent will get to know his children and rather than try to fit them into a specific mold (eg. “I want my child to be what I couldn’t be but always wanted to be), will guide the child in testing different roads to get an idea of the best way for the child to go. Then, with a good understanding of the personality and capabilities of the child, mom and dad encourage the child to go down the road he (or she) will be good at. It does no good to force an outdoorsman to be a bookworm, nor a bookworm to be a sports nut, nor someone with mechanical aptitude to be a philosopher. Spend time with your children, learn who they are, help to mold them according to their abilities. You will not be surprised at their successes or failures, and you will be there for them during both. They will never forget this blessing you’ve given them.