Be strong for the battle; take courage, and strengthen thyself as much as thou canst. It is an ironical concession, like that, Go, and prosper.
Related Commentaries of 2 Chronicles 25:8
2 Chronicles 25:8
8 But if thou wilt go, do it, be strong for the battle: God shall make thee fall before the enemy: for God hath power to help, and to cast down.