2 Kings 3:21

And when ... heard... they gathered. — Now all the Moabites had heard... and had gathered themselves:

literally, had been summoned, called together (Judges 7:23).

All that were able to put on armour. — From every one girding on a girdle, and upwards — i.e., all of adult age, all who could bear arms. It was a levy en masse of the male population for the defence of the country.

Stood in. — Had taken their stand on the frontier.