'Enemy' in the Bible

“If Your people Israel have been defeated by an enemy because they have sinned against You, and they return to You and confess Your name, and pray and make supplication before You in this house,

But if you do go [in spite of this warning], be strong and courageous for battle; yet God will cause you to stumble and fall before the enemy, for God has power to help and to cause people to stumble.”

Under their command was an army of 307,500, who could wage war with great power, to help the king against the enemy.