'Firstborn of Israel' in the Bible

These be the heads of their fathers' houses: The sons of Reuben the firstborn of Israel; Hanoch, and Pallu, Hezron, and Carmi: these be the families of Reuben.

The descendants of Reuben, the firstborn of Israel, their genealogies according to their clans, according to {their families}, according to [the] number of names, every male individually from {twenty years old} and above, everyone who [is able] to go to war:

since every firstborn of Israel belongs to me, from human beings to livestock. On the same day that I destroyed all the firstborn in the land of Egypt, I consecrated them to myself,

Reuben, the firstborn of Israel: the children of Reuben: of Enoch, the family of the Enochites; of Pallu, the family of the Palluites;

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.