Her sons — The sons of Azubah, who is by way of distinction called his wife, when Jerioth probably was only his concubine, and, it may seem, barren: therefore upon Azubah's death he married another wife. And those other sons of this Caleb mentioned, 1 Chronicles 2:42, are his sons by some other wife distinct from all these.
Related Commentaries of 1 Chronicles 2:18
1 Chronicles 2:18
18 And Caleb the son of Hezron begat children of Azubah his wife, and of Jerioth: her sons are these; Jesher, and Shobab, and Ardon.