Albert Barnes Commentary 1 Chronicles 2:42

"And the sons of Caleb the brother of Jerahmeel were Mesha his first-born, who was the father of Ziph; and the sons of Mareshah the father of Hebron." — 1 Chronicles 2:42 (ASV)

A third line of descent from Caleb, the son of Hezron, is mentioned—likely his children by a different mother, perhaps Jerioth (1 Chronicles 2:18). The supposed omissions in this verse have been supplied as follows:

1. “Mesha, the father of Ziph; and the sons of Ziph, Mareshah, the father of Hebron;” or
2. “Mareshah, the father of Ziph; and the sons of Mareshah, the father of Ziph, Hebron.”

Ziph, like Jorkoam (1 Chronicles 2:44) and Beth-zur (1 Chronicles 2:45), is the name of a place where the respective chiefs (“fathers”) settled. Similarly, Madmannah, Machbenah, and Gibea (1 Chronicles 2:49), Kirjath-jearim (Joshua 9:17), Bethlehem, and Beth-gader (Jedur, 1 Chronicles 2:51) are unmistakable names of places in this list. It is improbable that these names were ever borne by people.