According to Moses, this verse tells about the families that came from Ephraim, who was one of Joseph's sons. It lists the groups or clans named after Shuthelah, Becher, and Tahan, showing how big Ephraim's family became.
Numbers 26:35: These [are] the sons of Ephraim after their families: of Shuthelah, the family of the Shuthalhites: of Becher, the family of the Bachrites: of Tahan, the family of the Tahanites. [Becher: also called, Bered]
This verse lists the sons of Ephraim but does not mention Becher, contradicting the genealogy provided in Numbers 26:35.
1 Chronicles 7:20: And the sons of Ephraim; Shuthelah, and Bered his son, and Tahath his son, and Eladah his son, and Tahath his son,