The sword, judgment, or rather, the sword of judgment, or of vengeance, i.e. war, whereby thou judgest and punishest thy people for their sins. Compare Leviticus 26:25.
Related Commentaries of 2 Chronicles 20:9
2 Chronicles 20:9
9 If, when evil cometh upon us, as the sword, judgment, or pestilence, or famine, we stand before this house, and in thy presence, (for thy name is in this house,) and cry unto thee in our affliction, then thou wilt hear and help.