How does the covenant inheritance work for "Abraham's seed"?

"Israel" is a name given to Abraham's grandson before it becomes the name of a nation, and the transmission of blessings across generations is a fascinating theme in Genesis. It is not always a straightforward inheritance! We are left pondering what this means for us who claim to be in some spiritual sense the "descendants of Abraham". In particular, there's a challenge in these stories to celebrate the way God bestows blessings on those different from ourselves.