What was the Birthright? What, specifically, did Esau lose when he lost the birthright, and what did Jacob gain? What did the birthright represent, and why was it so highly prized by Jacob?
When Esau lost his birthright, he lost a greater ownership of his father's property, as well as the position of leader of the family (thinking of family as a whole tribe of people). Jacob may have prized the birthright out of greed, but it's worth mentioning that God spoke to Rebekah in Genesis 25:22-23 and told her that the younger of her sons would rule over the elder. While it doesn't say that this is the case anywhere in the Bible, If Rebekah had told Jacob of this, perhaps he felt he was doing the will of God. This might also explain why Rebekah helped him in deceiving his father (Genesis 27). Again, this is only speculation on my part. You can read more about the Hebrew birthright here: http://www.bible-history.com/isbe/B/BIRTHRIGHT/