Then Asa and his army pursued them as far as Gerar. The Cushites fell and could not recover, for they were crushed before the LORD and His army. So the people of Judah carried off a great amount of plunder
Here is, I. Disturbance given to the peace of Asa's kingdom by a formidable army of Ethiopians that invaded them, Ch2 14:9, Ch2 14:10. Though still they sought God, yet this fear came upon them, that their faith in God might be tried, and that God might have an opportunity of doing great things for them.
Commenting on 2 Chronicles 14:9-15
And they smote all the cities round about Gerar,.... The cities of the Philistines, who were auxiliaries and confederates with these Ethiopians, and colonies from them, according to Theodoret, and who says, about Eleutheropolis was a place, called, in his time, Geraron Saton: for the fear of the Lord came upon them; so that they had no power to defend themselves, and oppose the men...
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.