2 Kings 3:21

And when all the Moabites heard that the kings were come up to fight against them, this had taken place in the course of the seven days while the attacking army was approaching, they gathered all that were able to put on armor, summoning all those that were able to gird themselves, that is, to bear arms, and upward, not only the very young, but also all the older men, and stood in the border, drawn up in battle-line along the boundary of their country.