What was the birthright in an Old Testament family?
In the Old Testament setting described, the birthright was the spiritual side of the family position. The eldest son functioned as the family priest and spiritual leader. In Abraham's line, it also carried the promise that the Messiah, the Redeemer, would come through that line.
Les teaches that the birthright was the spiritual side of the family position. The eldest son was more or less the priest of the family—the spiritual leader. But with regard to the little family coming out of Abraham, it was more than just being the family priest: it was through this line that the promised Messiah, the Redeemer, would come. This made it all important that God's sovereign will be accomplished. Esau, according to his being born first, could have been in the line of the Messiah, but he canceled it because of his no faith, and it fell to Jacob. Jacob then got the birthright, not really by deceiving Esau. Les also notes that in the ancient Middle Eastern world, even pagan kings made decrees that could not be changed, right or wrong, and Isaac's decree giving Jacob the blessing stood the same way.