Albert Barnes Commentary 1 Chronicles 2:50

"These were the sons of Caleb, the son of Hur, the first-born of Ephrathah: Shobal the father of Kiriath-jearim," — 1 Chronicles 2:50 (ASV)

Caleb the son of Hur — Hur was the son, not the father, of Caleb (1 Chronicles 2:19). The text should perhaps be read: “These (the list in 1 Chronicles 2:42–49) were the sons of Caleb. The sons of Hur, the firstborn of Ephrathah, were Shobal, etc.”