Charles Ellicott Commentary 1 Chronicles 7:39

"And the sons of Ulla: Arah, and Hanniel, and Rizia." — 1 Chronicles 7:39 (ASV)

The sons of Ulla. —Apparently Ulla is not connected with the preceding genealogy. But he seems to be the same as Ara (1 Chronicles 7:38). ‘Arâ’ is a very curious form, and may be due to a copyist’s eye having wandered to Be-era at the end of the last verse; ‘Ullâ’ is intelligible, and probably correct. If the identification is allowed, we get a complete concatenation from 1 Chronicles 7:30–39.

Arah is in Hebrew quite different from Ara.