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.
God was not only faithful to bless as He had promised, but He also judged sin as He had said He would (1 Chronicles 5:25-26). This is the reason the Transjordanian tribes went into captivity.