Charles Ellicott Commentary 1 Chronicles 2:6-8

"And the sons of Zerah: Zimri, and Ethan, and Heman, and Calcol, and Dara; five of them in all. And the sons of Carmi: Achar, the troubler of Israel, who committed a trespass in the devoted thing. And the sons of Ethan: Azariah." — 1 Chronicles 2:6-8 (ASV)

The sons of Zerah. —From this point, our narrative ceases to depend entirely upon the data of Genesis.