Charles Ellicott Commentary 2 Chronicles 26:13

"And under their hand was an army, three hundred thousand and seven thousand and five hundred, that made war with mighty power, to help the king against the enemy." — 2 Chronicles 26:13 (ASV)

Under their hand. —Or, at their side, meaning, under their command.

An army. —See margin. An armed force, or, warlike host (chêl çâbâ’); an expression only found elsewhere in 1 Chronicles 20:1.

Three hundred thousand ... five hundred. —This fairly agrees with the statement respecting the total of Amaziah’s army (300,000) in 2 Chronicles 25:5.

That made war with mighty power. —Literally, a doer of battle with strength of might (sturdy strength, kôaḥ ḥayil, a unique phrase). Each chief was thus at the head of about a hundred and twenty men, who formed his troop (gedûd, 2 Chronicles 26:11). (Compare the expression, “captains of hundreds.”) The actual number in each century may have varied, as in the Roman army.