When Azubah died, Caleb married Ephrath, who bore to him Hur.
The text about Caleb appears tangled in our version: he is called father of Hur in one place and son of Hur in another. The latter passage has been copied wrong and should read 'Hur the son of Caleb.' Azubah was his wife; Jerioth was a secondary wife, mother of those children named.
AI summary
Commenting on 1 Chronicles 2:18-55
And the sons of Jerahmeel, the firstborn of Hezron, were Ram the firstborn,.... So called by his father after the name of his brother, see Ch1 2:9. and Bunah, and Oren, and Ozem, and Ahijah; or "of Ahijah", as some (r) render it, this being the name of his wife, who bare him the sons before named, since mention is made of another wife in the next verse.
Caleb here is plainly a shortened form, so all exegetes recognize it. The first half of verse eighteen is obscure and likely corrupt in the text. We must read it as 'Caleb begat with Azubah' and separately 'with Jerioth', one was his wife, the other a secondary partner, and only one wife's sons are listed before her death in verse nineteen.
AI summary
Commenting on 1 Chronicles 2:18-24