'Birthright' in the Bible

The sons of Reuben the firstborn of Israel (for he was the firstborn; but, because he defiled his father's couch, his birthright was given to the sons of Joseph the son of Israel; and the genealogy is not to be reckoned after the birthright.

For Judah prevailed above his brothers, and of him came the prince; but the birthright was Joseph's:)