John Gill Commentary 1 Chronicles 4:5

"And Ashhur the father of Tekoa had two wives, Helah and Naarah." — 1 Chronicles 4:5 (ASV)

And Ashur the father of Tekoa
A son of Hezron by Abiah, (1 Chronicles 2:24)

had two wives, Helah and Naarah ;
as Lamech had, polygamy not being reckoned unlawful in those times.