2 Chronicles 13:3

Abijah set the battle in array R.V. Abijah joined battle.

four hundred thousand … eight hundred thousand It is to be noted that the Chronicler does notexpressly say that these two huge armies met on one field of battle. In 2 Samuel 24:9 (David's numbering) the fighting men of Israel are given at 800,000 and the fighting men of Judah at 500,000. Similarly the Chronicler may mean to state here the whole armed strength of Israel and Judah without committing himself to the number of those who actually took the field. The language is not precise, for the Chronicler is little interested in military details. It should be noted, moreover, that the numbers precede the mention of the battlefield, and therefore are not necessarilyto be included in the account of the fight.

Similarly it is to be noted that the Chronicler does notsay in 2 Chronicles 13:17 that 500,000 of Israel fell in one day(contrast 2 Chronicles 28:6). Rather, he implies that the war continued for some time (2 Chronicles 13:19).