John Gill Commentary 1 Chronicles 2:45

"And the son of Shammai was Maon; and Maon was the father of Beth-zur." — 1 Chronicles 2:45 (ASV)

And the son of Shammai was Maon
Who gave name to a city in the tribe of Judah, (Joshua 15:55) see (1 Samuel 23:24 1 Samuel 23:25) (25:2) and Maon was the father of Bethzur ;
prince of a very strong fortified city of this name in the same tribe, (Joshua 15:58) , unless this was a son of Maon's, from whom the city had its name.