II Chronicles - Chapter 14
Asa was a righteous king, who fought to abolish idolatry within his borders. He encouraged the people of Judah to seek out G-d and to follow His Torah. Things were pretty uneventful under Asa and the people were content. They built fortified cities as defenses against invasion.
Asa's army was well-armed, with warriors from the Tribes of Judah and Benjamin. They were attacked by Zerach of Kush. According to the Talmud (Peaschim 119a), Zerach had captured from Shishak the treasures that Shishak had captured from Asa's grandfather Rechavam. These he carried into battle as a means of intimidation. Asa prayed to G-d for help in the battle and G-d answered him; the army of Judah pursued the Kushite army to Gerar, leaving the fallen in their wake. In this way, Asa recaptured the wealth that had been taken by Egypt. The army of Judah conquered the cities around Gerar and captured additional spoils.