C. F. Keil and Franz Delitzsch on 2 Chronicles 14:13

2Ch 14:13 “They smote all the cities round about Gerar,” which, as we must conclude from this, had made common cause with the Cushites, being inhabited by Philistines; for the fear of Jahve had fallen upon them. יהוה פּחד יהוה . here, and in 2Ch 17:10; 2Ch 20:29, as in 1Sa 11:7, the fear of the omnipotence displayed by Jahve in the annihilation of the innumerable hostile army. In these cities Judah found much booty.