Matthew Poole and continuators on Exodus 6:14

14 These be the heads of their fathers houses : The sons of Reuben, the first-born of Israel, Hanoch and Pallu, Hezron and Carmi: these be the families of Reuben.

This genealogy he describes here to shew the linage of Moses and Aaron, by whom this great work was to be effected. Onely he premiseth in brief the genealogy of his two elder brethren, Reuben and Simeon, to make way for the third, which he intended more largely to insist upon. And he mentions them rather than any other, either to advance the favour of God in preferring that tribe before the descendants of their elder brethren: or to shew that, although the parents were sharply censured and rather cursed then blessed by Iacob, Gen. 49. yet their posterity was not rejected by God, but received to mercy, and admitted to the same priviledge with their brethren.

Marginal references: Gen. 46. 9. 1 Chron. 5. 3.