2 Chronicles 13:3

3. Set the battle in array Literally, joined the battle; that is, opened the war; began the fight.

Jeroboam also set the battle in array The verb here is different from that translated by the same words above. Abijah began the war in order to punish Jeroboam and Israel for rebellion, and Jeroboam ordered out his army for defense. The numbers 800,000 and 400,000 seem incredibly large; but perhaps the author only meant to designate the forces which each kingdom could command, not to say that all these 1,200,000 were engaged in any one battle. Compare the number of fighting men in David’s time. 2 Samuel 24:9.