'Firstborn of Israel' in the Bible

Now the sons of Reuben the firstborn of Israel, (for he was the firstborn; but, forasmuch as he defiled his father's bed, his birthright was given unto the sons of Joseph the son of Israel: and the genealogy is not to be reckoned after the birthright.

The sons, I say, of Reuben the firstborn of Israel were, Hanoch, and Pallu, Hezron, and Carmi.