Jamieson, Fausset and Brown on 1 Chronicles 5:1

CHAPTER 5

1Ch 5:1-10. The Line of Reuben.

1. Now the sons of Reuben--In proceeding to give this genealogy, the sacred historian states, in a parenthesis (1Ch 5:1, 2), the reason why it was not placed first, as Reuben was the oldest son of Jacob. The birthright, which by a foul crime he had forfeited, implied not only dominion, but a double portion (De 21:17); and both of these were transferred to Joseph, whose two sons having been adopted as the children of Jacob (Ge 48:5), received each an allotted portion, as forming two distinct tribes in Israel. Joseph then was entitled to the precedency; and yet, as his posterity was not mentioned first, the sacred historian judged it necessary to explain that "the genealogy was not to be reckoned after the birthright," but with a reference to a superior honor and privilege that had been conferred on Judah--not the man, but the tribe, whereby it was invested with the pre-eminence over all the other tribes, and out of it was to spring David with his royal lineage, and especially the great Messiah (He 7:14). These were the two reasons why, in the order of enumeration, the genealogy of Judah is introduced before that of Reuben.