Charles Ellicott Commentary 1 Chronicles 6:20-21

"Of Gershom: Libni his son, Jahath his son, Zimmah his son, Joah his son, Iddo his son, Zerah his son, Jeatherai his son." — 1 Chronicles 6:20-21 (ASV)

The genealogy of the Gershonites in seven successive generations. It does not occur in the Pentateuch. This and the two following lists of Kohathites and Merarites are symmetrical in plan, but not in the number of names included.