The sons of Zerah: Zimri, Ethan, Heman, Calcol, and Dara, five in all.
Here is, I. The family of Jacob. His twelve sons are here named, that illustrious number so often celebrated almost throughout the whole Bible, from the first to the last book of it. At every turn we meet with the twelve tribes that descended from these twelve patriarchs.
Commenting on 1 Chronicles 2:1-17
And the sons of Ethan; Azariah. Including his posterity, see Gen 46:23, the posterity of the other three sons of Zerah are not mentioned, either because the writer could not find the genealogy of them, as Kimchi; or rather, as he thinks, he cuts short the genealogy of Zerah, because the kingdom did not proceed from him, and returns to the genealogy of Hezron, from...
Zimri, and Ethan, and Heman, and Calcol, and Dara--These five are here stated to be the sons of Zerah, that is, of Ezra, whence they were called Ezrahites (Kg1 4:31). In that passage they are called "the sons of Mahol," which, however, is to be taken not as a proper name, but appellatively for "sons of music, dancing," &c.