'Birthright' in the Bible

And the sons of Reuben, the oldest son of Israel, (for he was the oldest son, but, because he made his father's bride-bed unclean, his birthright was given to the sons of Joseph, the son of Israel; but he is not to be given the place of the oldest.

Though Judah became stronger than his brothers, and from him came the ruler, the birthright was Joseph's:)