Moroni continues the theme from verses 20–21. Even though God is powerful to save, we are to work towards our salvation. “God will [not] look upon you as guiltless while ye sit still and behold these things.”
Moroni will not sit back and only watch. If Pahoran does not act to supply the armies, Moroni will turn those armies against him, and use them to take away those in the government who are not sufficiently supporting the troops in the field.
There is an interesting phrase used in verses 23 and 24. Moroni speaks of cleansing the “inward vessel.” This may be an allusion to the concept of purity under the law of Moses. There have been debates about whether or not the cleanliness of the inside of a vessel could be contaminated from the outside of the same vessel. In this case, Moroni is suggesting that the inward vessel (the government in Zarahemla) is impure, and that the outer vessel (the armies), would be required to cleanse the inward vessel.